Orthopedic Fixation Strut Swapping

ABSTRACT

A plurality of three-dimensional fixator graphical representations may include graphical indications of a strut swap range. A plurality of replaced strut graphical representations may change from a first rendering state in a swap start fixator graphical representation to a second rendering state in a swap end fixator graphical representation. A plurality of replacement graphical representations may change from the second rendering state in the swap start fixator graphical representation to the first rendering state in the swap end fixator graphical representation. In some examples, the plurality of replaced strut graphical representations may gradually fade out from a swap start stage to a swap end stage, and the plurality of replacement strut graphical representations may gradually fade in from a swap start stage to a swap end stage. Additionally, a treatment plan including at least one interfamily strut swap may be generated for manipulating a fixator to correct a deformity.

BACKGROUND

Techniques used to treat fractures and/or deformities of anatomicalstructures, such as bones, can include the use of external fixators,such as hexapods and other fixation frames, which are surgically mountedto anatomical structure segments on opposed sides of a fracture site. Apair of radiographic images is taken of the fixator and anatomicalstructure segments at the fracture site. Data from the images is thenmanipulated to construct a three-dimensional representation of thefixator and the anatomical structures segments that can be used indeveloping a treatment plan, which may for example comprise realigningthe anatomical structure segments through adjustments to the fixator.

Existing techniques for controlling fixator manipulation may, however,involve a number of limitations that may introduce inefficiency,complication, and unreliability. In particular, the manipulations to thefixator may include one or more strut swaps, which is a swap (i.e.,exchange) of a replaced strut for a different sized replacement strut byremoving the replaced strut from the fixator and replacing it with thereplacement strut. There may typically be a specified range of time inwhich a strut swap may be performed, referred to as a strut swap range.Certain conventional techniques may be limited with respect to theability to indicate when strut swap ranges occur (e.g., on which days ofa treatment plan a strut swap may be performed) to users in a clear andefficient manner. These techniques may also be limited with respect tothe ability to indicate an amount (e.g., percentage) of a strut swaprange duration that is remaining and/or that has expired at anyparticular day within the strut swap range. Additionally, in someexamples, although multiple different types or families of struts (e.g.,standard, quick adjust, etc.) may sometimes be available for use with afixator, users may often be limited to selecting and using struts fromonly a single family. This is because some techniques may not allowcalculation of treatment plans that include interfamily strut swaps(i.e. swaps of struts between different strut families). This may beproblematic, for example, because struts from different families mayhave different length ranges, and some corrections may require a shorteror longer length than is available from a particular selected strutfamily.

SUMMARY

Techniques for orthopedic fixation strut swapping are described herein.In some examples, a plurality of fixator graphical representations, suchas three-dimensional graphical representations, may be provided of afixator that includes rings and struts to correct a deformity of firstand second anatomical structure segments. Specifically, a computingsystem may first determine manipulations to the fixator for correctionof the deformity. The manipulations may comprise a plurality ofadjustments to strut lengths and a strut swap from a replaced strut to areplacement strut. The manipulations may be performed throughout a setof stages (e.g., days), and the strut swap may be performable in a strutswap range comprising a sub-set of stages within the set of stages. Thesub-set of stages may include a swap start stage and a swap end stage.The computing system may then generate the plurality of fixatorgraphical representations. The plurality of fixator graphicalrepresentations may include a swap start fixator graphicalrepresentation and a swap end fixator graphical representation. Each ofthe plurality of fixator graphical representations may include arespective one of a plurality of replaced strut graphicalrepresentations and a respective one of a plurality of replacement strutgraphical representations. The plurality of replaced strut graphicalrepresentations may change from a first rendering state in the swapstart fixator graphical representation to a second rendering state inthe swap end fixator graphical representation. The plurality ofreplacement strut graphical representations may change from the secondrendering state in the swap start fixator graphical representation tothe first rendering state in the swap end fixator graphicalrepresentation. In some examples, the first rendering state is a moreopaque state and the second rendering state is a less opaque state thatis less opaque than the more opaque state. In some examples, theplurality of replaced strut graphical representations and the pluralityof replacement strut graphical representations have linear rates ofchange between the first rendering state and the second rendering state.In some examples, the plurality of fixator graphical representationsinclude one or more intermediate fixator graphical representations thatrepresent the fixator at one or more intermediate stages between theswap start stage and a swap end stage, and the one or more intermediatefixator graphical representations may be rendered according to thelinear rates of change. In this manner, the plurality of replaced strutgraphical representations may gradually fade out from the swap startstage to the swap end stage, and the plurality of replacement strutgraphical representations may gradually fade in from the swap startstage to the swap end stage.

In some examples, a treatment plan including at least one interfamilystrut swap may be generated for manipulating a fixator including ringsand struts to correct a deformity of first and second anatomicalstructure segments. A computing system may determine positions andorientations of the first and the second anatomical structure segmentsin three-dimensional space. The computing system may then determinemanipulations to the fixator for correction of the deformity. Themanipulations may include a plurality of adjustments to strut lengthsand an interfamily strut swap between a first strut in a first strutfamily and a second strut in a second strut family. The computing systemmay then provide, to one or more users, indications of the manipulationsto the fixator. The first strut family may include a first plurality ofstruts having different size ranges with respect to one another. Thesecond strut family may include a second plurality of struts havingdifferent size ranges with respect to one another. In some examples, thefirst strut family may be a standard strut family and the second strutfamily may be a quick adjust strut family (or vice versa). In someexamples, a first maximum length of a longest strut in the first strutfamily may be longer than a second maximum length of a longest strut inthe second strut family. In some examples, a first minimum length of ashortest strut in the first strut family may be shorter than a secondminimum length of a shortest strut in the second strut family. In someexamples, an inclusion of the interfamily strut swap in themanipulations may be based on a determination that the correction of thedeformity cannot be performed using struts from only a single strutfamily. In some examples, the manipulations may be determined based atleast in part on a rule to select a treatment plan with a fewest amountof strut swaps from a plurality of available treatment plans. In someexamples, the manipulations may be determined based at least in part ona rule to select a treatment plan with at least one strut swap having atleast a minimum strut swap duration from a plurality of availabletreatment plans.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

The foregoing summary, as well as the following detailed description ofthe preferred embodiments of the application, will be better understoodwhen read in conjunction with the appended drawings. For the purposes ofillustrating the methods and/or techniques of orthopedic fixation withimagery analysis, there are shown in the drawings preferred embodiments.It should be understood, however, that the instant application is notlimited to the precise arrangements and/or instrumentalities illustratedin the drawings, in which:

FIG. 1 is a perspective view of a fixation assembly positioned forimaging in accordance with an embodiment;

FIG. 2 is a perspective view of an example imaging process of thefixation assembly illustrated in FIG. 1;

FIGS. 3A and 3B are flow diagrams illustrating an example process forcontrolling manipulation of a fixation apparatus to correct ananatomical structure deformity;

FIG. 4 is a screen shot of an example interface for selecting aPerspective Frame Matching (PFM) technique;

FIG. 5 is a screen shot of an example configuration information entryinterface for the PFM technique;

FIG. 6 is a screen shot of an example first image information entryinterface for the PFM technique;

FIG. 7 is a screen shot of an example close-up assist interface for thePFM technique;

FIGS. 8A-8H are screen shots of an example second image informationentry interface for the PFM technique;

FIG. 9 is a screen shot of example deformity parameter interface for thePFM technique;

FIG. 10 is a screen shot of an example mounting parameter interface forthe PFM technique;

FIG. 11 is a screen shot of a first example treatment plan interface forthe PFM technique;

FIG. 12 is a screen shot of a second example treatment plan interfacefor the PFM technique;

FIG. 13 is a screen shot of a third example treatment plan interface forthe PFM technique;

FIG. 14 is a flow diagram illustrating an example process for providinga plurality of fixator graphical representations including graphicalstrut swap range indications;

FIG. 15 is a diagram illustrating an example fixator graphicalrepresentation prior to a strut swap range;

FIG. 16 is a diagram illustrating an example fixator graphicalrepresentation at a start stage of a strut swap range;

FIG. 17 is a diagram illustrating example fixator graphicalrepresentation at an intermediate stage of a strut swap range;

FIG. 18 is a flow diagram illustrating an example fixator graphicalrepresentation at a midpoint stage of a strut swap range;

FIG. 19 is a diagram illustrating example fixator graphicalrepresentation at another intermediate stage of a strut swap range;

FIG. 20 is a diagram illustrating an example fixator graphicalrepresentation at an end stage of a strut swap range;

FIG. 21 is a diagram illustrating an example fixator graphicalrepresentation subsequent to a strut swap range;

FIG. 22 is a flow diagram illustrating an example process for generatinga treatment plan including an interfamily strut swap;

FIG. 23 is a block diagram of an example computing device for use inaccordance with the present disclosure.

DETAILED DESCRIPTION

For convenience, the same or equivalent elements in the variousembodiments illustrated in the drawings have been identified with thesame reference numerals. Certain terminology is used in the followingdescription for convenience only and is not limiting. The words “right”,“left”, “top” and “bottom” designate directions in the drawings to whichreference is made. The words “inward”, “inwardly”, “outward”, and“outwardly” refer to directions toward and away from, respectively, thegeometric center of the device and designated parts thereof. Theterminology intended to be non-limiting includes the above-listed words,derivatives thereof and words of similar import.

Referring initially to FIG. 1, bodily tissues, for instance first andsecond anatomical structure segments 102, 104, can be aligned and/ororiented to promote union or other healing between the bodily tissues.Anatomical structures may include, for example, anatomical tissue andartificial anatomical implants. Anatomical tissue may include, forexample, bone or other tissue in the body. The alignment and/ororientation of the bodily tissues can be achieved by connecting thebodily tissues to an adjustable fixation apparatus, such as orthopedicfixator 100. The orthopedic fixator can comprise an external fixationapparatus that includes a plurality of discrete fixator members thatremain external to the patient's body, but that are attached torespective discreet bodily tissues, for example with minimally invasiveattachment members. A fixation apparatus may include, for example, adistraction osteogenesis ring system, a hexapod, or a Taylor spatialframe. By adjusting the spatial positioning of the fixator members withrespect to each other, the respective bodily tissues attached theretocan be reoriented and/or otherwise brought into alignment with eachother, for example to promote union between the bodily tissues duringthe healing process. The use of external orthopedic fixators incombination with the imagery analysis and positioning techniquesdescribed herein can be advantageous in applications where directmeasurement and manipulation of the bodily tissues is not possible,where limited or minimally invasive access to the bodily tissues isdesired, or the like. Some examples of orthopedic fixators and their usefor correcting deformities of anatomical structure segments, as well astechniques for performing imagery analysis on the fixators andanatomical structure segments are described in U.S. Pat. No. 9,642,649,entitled “ORTHOPEDIC FIXATION WITH IMAGERY ANALYSIS,” issued on May 9,2017, the entirety of which is hereby incorporated by reference.

The fixator members can be connected to each other via adjustmentmembers, the adjustment members configured to facilitate the spatialrepositioning of the fixator members with respect to each other. Forexample, in the illustrated embodiment, the orthopedic fixator 100comprises a pair of fixator members in the form of an upper fixator ring106 and a lower fixator ring 108. The fixator rings 106, 108 can beconstructed the same or differently. For instance, the fixator rings106, 108 can have diameters that are the same or different. Similarly,the fixator rings 106, 108 can be constructed with varying crosssectional diameters, thicknesses, etc. It should be appreciated that thefixator members of the orthopedic fixator 100 are not limited to theillustrated upper and lower fixator rings 106, 108, and that theorthopedic fixator 100 can be alternatively constructed. For example,additional fixator rings can be provided and interconnected with thefixator ring 106 and/or 108. It should further be appreciated that thegeometries of the fixator members are not limited to rings, and that atleast one, such as all of the fixator members can be alternativelyconstructed using any other suitable geometry.

The first and second anatomical structure segments 102, 104 can berigidly attached to the upper and lower fixator rings 106, 108,respectively, with attachment members that can be mounted to the fixatorrings 106, 108. For example, in the illustrated embodiment, attachmentmembers are provided in the form of attachment rods 110 and attachmentwires 112.

The rods 110 and the wires 112 extend between proximal ends attached tomounting members 114 that are mounted to the fixator rings 106, 108, andopposed distal ends that are inserted into or otherwise secured to theanatomical structure segments 102, 104. The mounting members 114 can beremovably mounted to the fixator rings 106, 108 at predefined pointsalong the peripheries of the fixator rings 106, 108, for example bydisposing them into threaded apertures defined by the fixator rings.With respect to each fixator ring 106, 108, the mounting members 114 canbe mounted to the upper surface of the ring, the lower surface of thering, or any combination thereof. It should be appreciated that theattachment members are not limited to the configuration of theillustrated embodiment. For example, any number of attachment members,such as the illustrated rods 110 and wires 112 and any others, can beused to secure the anatomical structure segments to respective fixatormembers as desired. It should further be appreciated that one or more ofthe attachment members, for instance the rods 110 and/or wires 112, canbe alternatively configured to mount directly to the fixator rings 106,108, without utilizing mounting members 114.

The upper and lower fixator rings 106, 108 can be connected to eachother by at least one, such as a plurality of adjustment members. Atleast one, such as all, of the adjustment members can be configured toallow the spatial positioning of the fixator rings with respect to eachother to be adjusted. For example, in the illustrated embodiment, theupper and lower fixator rings 106, 108 are connected to each other witha plurality of adjustment members provided in the form of adjustablelength struts 116. It should be appreciated that the construction of theorthopedic fixator 100 is not limited to the six struts 116 of theillustrated embodiment, and that more or fewer struts can be used asdesired.

Each of the adjustable length struts 116 can comprise opposed upper andlower strut arms 118, 120. Each of the upper and lower strut arms 118,120 have proximal ends disposed in a coupling member, or sleeve 122, andopposed distal ends that are coupled to universal joints 124 mounted tothe upper and lower fixator rings 106, 108, respectively. The universaljoints of the illustrated embodiment are disposed in pairs spaced evenlyaround the peripheries of the upper and lower fixator rings 106, 108,but can be alternatively placed in any other locations on the fixatorrings as desired.

The proximal ends of the upper and lower strut arms 118, 120 of eachstrut 116 can have threads defined thereon that are configured to bereceived by complementary threads defined in the sleeve 122, such thatwhen the proximal ends of the upper and lower strut arms 118, 120 of astrut 116 are received in a respective sleeve 122, rotation of thesleeve 122 causes the upper and lower strut arms 118, 120 to translatewithin the sleeve 122, thus causing the strut 116 to be elongated orshortened, depending on the direction of rotation. Thus, the length ofeach strut 116 can be independently adjusted with respect to theremaining struts. It should be appreciated that the adjustment membersare not limited to the length adjustable struts 116 of the illustratedembodiment, and that the adjustment members can be alternativelyconstructed as desired, for example using one or more alternativegeometries, alternative length adjustment mechanisms, and the like.

The adjustable length struts 116 and the universal joints 124 by whichthey are mounted to the upper and lower fixator rings 106, 108, allowthe orthopedic fixator 100 to function much like a Stewart platform, andmore specifically like a distraction osteogenesis ring system, ahexapod, or a Taylor spatial frame. That is, by making lengthadjustments to the struts 116, the spatial positioning of the upper andlower fixator rings 106, 108, and thus the anatomical structure segments102, 104 can be altered. For example, in the illustrated embodiment thefirst anatomical structure segment 102 is attached to the upper fixatorring 106 and the second anatomical structure segment 104 is attached tothe lower fixator ring 108. It should be appreciated that attachment ofthe first and second anatomical structure segments 102, 104 to the upperand lower fixator rings 106, 108 is not limited to the illustratedembodiment (e.g., where the central longitudinal axes L1, L2 of thefirst and second anatomical structure segments 102, 104 aresubstantially perpendicular to the respective planes of the upper andlower fixator rings 106, 108), and that a surgeon has completeflexibility in aligning the first and second anatomical structuresegments 102, 104 within the upper and lower fixator rings 106, 108 whenconfiguring the orthopedic fixator 100.

By varying the length of one or more of the struts 116, the upper andlower fixator rings 106, 108, and thus the anatomical structure segments102 and 104 can be repositioned with respect to each other such thattheir respective longitudinal axes L1, L2 are substantially aligned witheach other, and such that their respective fractured ends 103, 105 abuteach other, so as to promote union during the healing process. It shouldbe appreciated that adjustment of the struts 116 is not limited to thelength adjustments as described herein, and that the struts 116 can bedifferently adjusted as desired. It should further be appreciated thatadjusting the positions of the fixator members is not limited toadjusting the lengths of the length adjustable struts 116, and that thepositioning of the fixator members with respect to each other can bealternatively adjusted, for example in accordance the type and/or numberof adjustment members connected to the fixation apparatus.

Repositioning of the fixator members of an orthopedic fixationapparatus, such as orthopedic fixator 100, can be used to correctdisplacements of angulation, translation, rotation, or any combinationthereof, within bodily tissues. A fixation apparatus, such as orthopedicfixator 100, utilized with the techniques described herein, can correcta plurality of such displacement defects individually or simultaneously.However, it should be appreciated that the fixation apparatus is notlimited to the illustrated orthopedic fixator 100, and that the fixationapparatus can be alternatively constructed as desired. For example, thefixation apparatus can include additional fixation members, can includefixation members having alternative geometries, can include more orfewer adjustment members, can include alternatively constructedadjustment members, or any combination thereof.

Referring now to FIG. 2, an example imaging of a fixation apparatus willnow be described in detail. The images can be captured using the same ordifferent imaging techniques. For example, the images can be acquiredusing x-ray imaging, computer tomography, magnetic resonance imaging,ultrasound, infrared imaging, photography, fluoroscopy, visual spectrumimaging, or any combination thereof.

The images can be captured from any position and/or orientation withrespect to each other and with respect to the fixator 100 and theanatomical structure segments 102, 104. In other words, there is norequirement that the captured images be orthogonal with respect to eachother or aligned with anatomical axes of the patient, thereby providinga surgeon with near complete flexibility in positioning the imagers 130.Preferably, the images 126, 128 are captured from different directions,or orientations, such that the images do not overlap. For example, inthe illustrated embodiment, the image planes of the pair of images 126,128 are not perpendicular with respect to each other. In other words,the angle α between the image planes of the images 126, 128 is not equalto 90 degrees, such that the images 126, 128 are non-orthogonal withrespect to each other. Preferably, at least two images are taken,although capturing additional images may increase the accuracy of themethod.

The images 126, 128 can be captured using one or more imaging sources,or imagers, for instance the x-ray imagers 130 and/or correspondingimage capturing devices 127, 129. The images 126, 128 can be x-rayimages captured by a single repositionable x-ray imager 130, or can becaptured by separately positioned imagers 130. Preferably, the positionof the image capturing devices 127, 129 and/or the imagers 130 withrespect to the space origin 135 of the three-dimensional space,described in more detail below, are known. The imagers 130 can bemanually positioned and/or oriented under the control of a surgeon,automatically positioned, for instance by a software assisted imager, orany combination thereof. The fixator 100 may also have a respectivefixator origin 145.

Referring now to FIGS. 3A and 3B, an example process for controllingmanipulation of a fixation apparatus including rings and struts tocorrect an anatomical structure deformity of first and second anatomicalstructure segments will now be described in detail. In particular, atoperation 310, first and second anatomical structure segments areattached to a fixation apparatus, for example as shown in FIG. 1 anddescribed in detail above. At operation, 312, first and second images ofthe fixation apparatus and the attached first and second anatomicalstructure segments are captured, for example as shown in FIG. 2 anddescribed in detail above.

The remaining operations of the process of FIGS. 3A and 3B (e.g.,operations 314-342) will now be described in association with atreatment technique referred to hereinafter as Perspective FrameMatching, in which images, such as post-operative x-rays, may be usedalong with a frame to generate deformity and mounting parameters for astrut adjustment plan. For example, referring now to FIG. 4, an exampletreatment planning technique selection interface 400-A is shown. In theexample of FIG. 4, the user has selected option 401 in order to use thePerspective Frame Matching (PFM) technique, which will now be describedin detail with reference to FIGS. 5-13.

Referring back to FIG. 3A, at operation 314, configuration informationassociated with a fixation apparatus is received, for example using oneor more graphical user interfaces of a computing system. In someexamples, the configuration information may include one or moregeometric characteristics (e.g., size, length, diameter, etc.) of one ormore elements of the fixation apparatus, such as struts, hinges, rings,and others. In some examples, the configuration information may includeinformation such as ring types (e.g., full ring, foot plate, etc.),indications of mounting points (e.g., ring holes) used for strutmounting, and other information. In some examples, the configurationinformation may also include information about marker elements, forexample that are mounted to components of the fixation apparatus, suchas struts, hinges, and rings. Referring now to FIG. 5, an exampleconfiguration information entry interface 500 is shown. As shown,interface 500 includes ring type indicators 501 and 502, which, in thisexample, are drop down menus that may be used to select ring types forthe proximal and distal rings, respectively. Indicators 501 and 502 areset to the “Full” option to indicate that the proximal and distal ringsare full rings. Interface 500 also includes diameter indicators 503 and504, which, in this example, are drop down menus that may be used toselect diameters or lengths for the proximal and distal rings,respectively.

The interface 500 also includes controls for entry of strut information.In particular, interface 500 includes six drop down menus 512 may eachbe used to indicate a size of a respective strut. Global strut sizeindicator 511 may also be used to globally select a size for all sixstruts. Length selectors 513 may be each be used to select a length of arespective strut. Length indicators 514 may be each be used to provide avisual representation of the lengths of the respective struts. It isnoted that the length indicators 514 do not necessarily depict theactual exact length of each strut, but rather represent the comparativelengths of the struts with respect to one another.

Save and Update button 516 may be selected to save and update theconfiguration information values shown in interface 500. In someexamples, selection of button 516 may cause interface 500 to displayand/or update a graphical representation 520 of the fixation apparatusgenerated based, at least in part, on the entered configurationinformation. The graphical representation 520 may be displayed using oneor more graphical user interfaces of a computing system. As shown,graphical representation 520 includes six struts that may be color-codedin multiple colors for easy identification. For example, in some cases,each of the struts (or at least two of the struts) may be shown indifferent colors with respect to one another. The struts in graphicalrepresentation 520 may have sizes, lengths, mounting points, and otherfeatures corresponding to entered configuration information. Graphicalrepresentation 520 also depicts the fixator rings, which may havediameters/lengths, ring types, and other features corresponding toentered configuration information. Graphical representation 520 may, forexample, improve efficiency and reliability by providing the user with avisual confirmation of information entered into interface 500, forexample to allow fast and easy identification of errors or otherproblems.

At operation 316, images of the fixation apparatus and the first andsecond anatomical structure segments attached thereto are displayed, forexample using one or more graphical user interfaces of a computingsystem. The displayed images may include images that were captured atoperation 312, such as using x-ray imaging, computer tomography,magnetic resonance imaging, ultrasound, infrared imaging, photography,fluoroscopy, visual spectrum imaging, or any combination thereof.Techniques for acquiring images of the fixation apparatus and the firstand second anatomical structure segments are described in detail aboveand are not repeated here. As set forth above, the acquired anddisplayed images need not necessarily be orthogonal to one another.Referring now to FIG. 6, an example first image information entryinterface 600 is shown. As shown, interface 600 includes images 601-Aand 601-B, which show the fixation apparatus and first and secondanatomical structure segments from different angles. In the example ofFIG. 6, image 601-A corresponds to an anteroposterior (AP) View, whileimage 601-B corresponds to a lateral (LAT) view. In some examples, thedisplayed images 601-A-B may be loaded and saved in computer memory, forexample in a library, database or other local collection of storedimages. The displayed images 601-A-B may then be selected and retrieved,acquired, and/or received from memory for display.

At operation 318, first image information is received, for example usingone or more graphical user interfaces of a computing system. The firstimage information may include indications of one or more locations,within the images, of at least part of one or more elements of thefixation apparatus. For example, the first image information may includeone or more indications of locations of struts, hinges, rings, and otherfixator elements. In some examples, the first image information may alsoinclude information about locations, within the images, of markerelements, for example that are mounted to components of the fixationapparatus, such as struts, hinges, and rings. In some cases, the firstimage information may include points representing locations of hingesand/or lines or vectors representing locations of struts. In someexamples, the first image information may be entered into a computingsystem by selecting or indicating one or more locations within thedisplayed images, for example using a mouse, keyboard, touchscreen orother user input devices. In particular, using one or more inputdevices, a user may select points or other locations in the images, drawlines, circles, and generate other graphical indications within theimages. For example, in some cases, a user may generate a point or smallcircle at a particular location in an image to indicate a location(e.g., center point) of a hinge within the image. As another example, insome cases, a user may generate a line and/or vector within an image toindicate a location and/or length of a strut within the image.

For example, as shown in FIG. 6, interface 600 includes six AP Viewstrut indicator buttons 611-A corresponding to each of the six struts ofthe fixation apparatus shown in AP View image 601-A. Each button 611-Aincludes text indicating a respective strut number (i.e., Strut 1, Strut2, Strut 3, Strut 4, Strut 5, Strut 6). Buttons 611-A may be selected bya user to indicate a strut for which first image information (e.g.,hinge locations, strut locations, etc.) will be provided by the user inAP View image 601-A. For example, in some cases, to provide first imageinformation for Strut 1 in AP View image 601-A, a user may first selectthe top strut indicator button 611-A (labeled with the text “Strut 1”)in order to indicate to the software that the user is about to providefirst image information for Strut 1 within AP View image 601-A. In somecases, the strut indicator button 611-A for Strut 1 may be pre-selectedautomatically for the user. Upon selection (or automatic pre-selection)of the strut indicator button 611-A for Strut 1, the user may proceed todraw (or otherwise indicate) a representation of Strut 1 within AP Viewimage 601-A. For example, in some cases, the user may use a mouse orother input device to select a location 621 (e.g., a center point) of aproximal hinge for Strut 1 within image 601-A. In some examples, theuser may then use a mouse or other input device to select a location 622(e.g., a center point) of the distal hinge of Strut 1 within image601-A. In some examples, the user may indicate the location and/orlength of Strut 1 by selecting the locations of the proximal and distalhinges and/or as the endpoints of a line or vector that represents thelocation and/or length of Strut 1. For example, as shown in FIG. 6, thesoftware may generate points or circles at the locations 621 and 622 ofthe proximal and distal hinges selected by the user within image 601-A.Additionally, the software may generate a line 623 representing thelocation and/or length of Strut 1 that connects the points or circles atthe locations 621 and 622 and of the proximal and distal hinges selectedby the user within image 601-A. Any other appropriate input techniquesmay also be employed by the user to indicate a location and/or length ofStrut 1 within image 610-A, such as generating line 623 by dragging anddropping a mouse, using a finger and/or pen on a touch screen, keyboard,and others. In some examples, the above described process may berepeated to draw points representing proximal and distal hinges andlines representing the locations and/or lengths of each of the sixstruts in the AP View image 601-A. Furthermore, the above describedprocess may also be repeated using LAT View strut indicator buttons611-B to draw points representing proximal and distal hinges and linesrepresenting the locations and/or lengths of each of the six struts inthe LAT View image 601-B.

In some examples, the first image information generated within images601-A and 601-B may include color-coded graphical representations of thestruts, for example to enable the graphical representations to be moreclearly associated with their respective struts. For example, in FIG. 6,the graphical representations (e.g., points, circles, and/or lines) ofStrut 1 in images 601A- and 601-B may be colored in red. This may matcha strut icon (which may also be colored red) displayed in the strutindicator buttons 611-A and 611-B for Strut 1 (displayed to the right ofthe text “Strut 1” in buttons 611-A and 611-B). As another example, inFIG. 6, the graphical representations (e.g., points, circles, and/orlines) of Strut 3 in images 601-A and 601-B may be colored in yellow.This may match a strut icon (which may also be colored yellow) displayedin the strut indicator buttons 611-A and 611-B for Strut 3 (displayed tothe right of the text “Strut 3” in buttons 611-A and 611-B).

FIG. 6 includes an AP View close-up assist checkbox 616-A and a LAT Viewclose-up assist checkbox 616-B, for example provided using one or moregraphical interfaces of a computing system. Selection of checkboxes616-A and 616-B may allow close-up views of areas of images 601-A and601-B surrounding the proximal and distal hinges of the struts that arecurrently being drawn by the user. This may enable more accurateindications of the locations (e.g., center points) of the hinges.Referring now to FIG. 7, close-up assist interface 700 depicts anotherAP View image 701 with the close-up assist being selected to provide aproximal hinge close-up assist view 702 and a distal hinge close-upassist view 703. As shown, proximal hinge close-up assist view 702provides an enlarged view of an area of AP View image 701 associatedwith the proximal hinge, while distal hinge close-up assist view 703provides an enlarged view of an area of AP View image 701 associatedwith the distal hinge. The user may manipulate (e.g., drag and drop) thelocation of the point/circle 721 in proximal hinge close-up assist view702 in order to more accurately depict the center point of the proximalhinge. The user may also manipulate (e.g., drag and drop) the locationof the point/circle 722 in distal hinge close-up assist view 703 inorder to more accurately depict the center point of the distal hinge. Asshould be appreciated, corresponding close-up assist views similar toviews 702 and 703 may also be provided for a respective LAT View image,for example using one or more graphical interfaces of a computingsystem.

Referring back to FIG. 6, to the right of buttons 611-A, are sixproximal hinge selector buttons 612-A. Additionally, to the right ofbuttons 612-A, are six distal hinge selector buttons 613-A. Furthermore,to the right of buttons 613-A, are six strut line selector buttons614-A. In some examples, buttons 612-A and/or 613-A may be selected touse the locations (e.g., center points) of the proximal and/or distalhinges indicated in AP View image 601-A in calculating positions andorientations of the first and the second anatomical structure segmentsand rings of the fixation apparatus in three-dimensional space (seeoperation 322). Additionally, in some examples, buttons 612-A and/or613-A may be selected to use the lines or vectors representing thelocation and/or length of struts indicated in AP View image 601-A incalculating positions and orientations of the first and the secondanatomical structure segments in three-dimensional space. Similarly,buttons 612-B, 613-B, and 614-B may be used to select the use oflocations (e.g., center points) of the proximal and/or distal hinges orstrut lines or vectors indicated in LAT View image 601-B in calculatingpositions and orientations of the first and the second anatomicalstructure segments in three-dimensional space.

Referring again to FIG. 3A, at operation 320, second image informationis received, for example using one or more graphical user interfaces ofa computing system. The second image information may include indicationsof one or more locations, within the images, of at least part of thefirst and the second anatomical structure segments. In some examples,the second image information may include indications of center lines ofthe first and the second anatomical structure segments and/or one ormore reference points (e.g., end points) of the first and the secondanatomical structure segments. In some examples, the second imageinformation may also include indications of locations of markerelements, for example implanted or otherwise associated with the firstand the second anatomical structure segments. In some examples, thesecond image information may be entered into a computing system byselecting or indicating one or more locations within the displayedimages, for example using a mouse, keyboard, touchscreen or other userinput devices. In particular, using one or more input devices, a usermay select points or other locations in the images, draw lines, circles,and generate other graphical indications within the images. For example,in some cases, a user may generate points or small circles at particularlocations in an image to indicate one or more reference points (e.g.,end points) of the first and the second anatomical structure segmentswithin the images. As another example, in some cases, a user maygenerate a line within an image to indicate a center line of the firstand the second anatomical structure segments within the images.

Referring now to FIG. 8A, an example second image information entryinterface 800 is shown. As shown, interface 800 includes AP View image601-A and LAT View image 601-B. Additionally, interface 800 includesbuttons 801-808, which may be used to assist in indication of anatomicalstructure center lines and reference points as will be described below.In particular, buttons 801 and 805 may be selected to indicate aproximal anatomical structure reference point in the AP View and LATView, respectively. Buttons 802 and 806 may be selected to indicate adistal anatomical structure reference point in the AP View and LAT View,respectively. Buttons 803 and 807 may be selected to indicate a proximalanatomical structure center line in the AP View and LAT View,respectively. Buttons 804 and 808 may be selected to indicate a distalanatomical structure center line in the AP View and LAT View,respectively. For example, as shown in FIG. 8A, a user may select button807 and then use one or more input devices to draw the center line 831for the proximal anatomical structure within LAT View image 601-B. Insome examples, the center line 831 may be colored red. Additionally, twoguidelines 832 are generated and displayed by the software on both sidesof the red center line. In some examples, the guidelines 832 may becolored green. These guidelines 832 may be displayed while the user isdrawing the center line 831 in order to assist the user in locating thecenter of the anatomical structure segment. The guidelines 832 may begenerated at equal distances from each side of the center line 831 andmay assist the user by, for example, potentially allowing the user tomatch (or nearly match) the guidelines 832 to sides of the anatomicalstructure segment. As shown in FIG. 8B, the user may select button 808and then use one or more input devices to draw the center line 841 forthe distal anatomical structure within LAT View image 601-B. As shown inFIG. 8C, the user may select button 803 and then use one or more inputdevices to draw the center line 851 for the proximal anatomicalstructure within AP View image 601-A. As shown in FIG. 8D, the user mayselect button 804 and then use one or more input devices to draw thecenter line 861 for the distal anatomical structure within AP View image601-A. As shown in FIGS. 8B-8D, guidelines 832 may also be displayed forassistance in drawing center lines 841, 851 and 861.

As shown in FIG. 8E, the user may select button 805 and then use one ormore input devices to indicate a reference point (e.g., end point) forthe proximal anatomical structure within LAT View image 601-B. As shown,a user has indicated a reference point 811 in LAT View image 601-B at anend point of the proximal anatomical structure segment. Additionally,upon indication of reference point 811, the software may generate anddisplay a corresponding dashed reference line 812 in AP View image601-A. The reference line 812 is a line drawn across AP View image 601-Athat passes through the location of the LAT View proximal referencepoint 811 within AP View image 601-A. The reference line 812 may,therefore, assist the user in determining the location of thecorresponding AP View proximal reference point, which may often be atthe intersection of the reference line 812 and the AP View proximalcenter line 851 within the AP View image 601-A. As shown in FIG. 8F, theuser may select button 801 and then use one or more input devices toindicate a reference point (e.g., end point) for the proximal anatomicalstructure within AP View image 601-A. In this example, the AP Viewproximal anatomical structure reference point 814 is indicated at theintersection of reference line 812 and the AP View proximal center line851 within the AP View image 601-A. The software may then generate anddisplay a corresponding dashed reference line 813 in the LAT View image601-B. The reference line 813 is a line drawn across LAT View image601-B that passes through the location of the AP View proximal referencepoint 814 within LAT View image 601-B. The reference line 813 may assistthe user by helping the user to confirm that the AP View reference point814 was placed correctly by showing how well it lines up relative to theLAT View reference point 811.

As shown in FIG. 8G, the user may select button 806 and then use one ormore input devices to indicate a reference point (e.g., end point) forthe distal anatomical structure within LAT View image 601-B. As shown, auser has indicated a reference point 815 in LAT View image 601-B at anend point of the distal anatomical structure segment. Additionally, uponindication of reference point 815, the software may generate and displaya corresponding dashed reference line 816 in AP View image 601-A. Thereference line 816 is a line drawn across AP View image 601-A thatpasses through the location of the LAT View distal reference point 815within AP View image 601-A. The reference line 816 may, therefore,assist the user in determining the location of the corresponding AP Viewdistal reference point, which may often be at the intersection of thereference line 816 and the AP View distal center line within the AP Viewimage 601-A. As shown in FIG. 8H, the user may select button 802 andthen use one or more input devices to indicate a reference point (e.g.,end point) for the distal anatomical structure within AP View image601-A. In this example, the AP View distal anatomical structurereference point 817 is indicated at the intersection of reference line816 and the AP View distal center line within the AP View image 601-A.The software may then generate and display a corresponding dashedreference line 818 in the LAT View image 601-B. The reference line 818is a line drawn across LAT View image 601-B that passes through thelocation of the AP View distal reference point 817 within LAT View image601-B. The reference line 818 may assist the user by helping the user toconfirm that the AP View reference point 817 was placed correctly byshowing how well it lines up relative to the LAT View reference point815.

Referring again to FIG. 3A, at operation 322, positions and orientationsof the first and second anatomical structure segments and rings of thefixation apparatus are determined in three-dimensional space. Forexample, in some cases, imaging scene parameters pertaining to fixator100, the anatomical structure segments 102, 104, imager(s) 130, andimage capturing devices 127, 129 are obtained. The imaging sceneparameters can be used in constructing a three-dimensionalrepresentation of the positioning of the anatomical structure segments102, 104 in the fixator 100, as described in more detail below. One ormore of the imaging scene parameters may be known. Imaging sceneparameters that are not known can be obtained, for example bymathematically comparing the locations of fixator elementrepresentations in the two-dimensional space of the x-ray images 126,128 to the three-dimensional locations of those elements on the geometryof the fixator 100. In a preferred embodiment, imaging scene parameterscan be calculated using a pin hole or perspective camera models. Forexample, the imaging scene parameters can be determined numericallyusing matrix algebra, as described in more detail below.

The imaging scene parameters can include, but are not limited to imagepixel scale factors, image pixel aspect ratio, the image sensor skewfactor, the image size, the focal length, the position and orientationof the imaging source, the position of the principle point (defined asthe point in the plane of a respective image 126, 128 that is closest tothe respective imager 130), positions and orientations of elements ofthe fixator 100, the position and orientation of a respective imagereceiver, and the position and orientation of the imaging source's lens.

In a preferred embodiment, at least some, such as all of the imagingscene parameters can be obtained by comparing the locations ofrepresentations of particular components, or fixator elements of thefixator 100 within the two-dimensional spaces of the images 126, 128,with the corresponding locations of those same fixator elements inactual, three-dimensional space. The fixator elements comprisecomponents of the orthopedic fixator 100, and preferably are componentsthat are easy to identify in the images 126, 128. Points, lines, conics,or the like, or any combination thereof can be used to describe therespective geometries of the fixator elements. For example, therepresentations of fixator elements used in the comparison could includecenter lines of one or more of the adjustable length struts 116, centerpoints of the universal joints 124, center points of the mountingmembers 114, and the like.

The fixator elements can further include marker elements that aredistinct from the above-described components of the fixator 100. Themarker elements can be used in the comparison, as a supplement to or inlieu of using components of the fixator 100. The marker elements can bemounted to specific locations of components of the fixator 100 prior toimaging, can be imbedded within components of the fixator 100, or anycombination thereof. The marker elements can be configured for enhancedviewability in the images 126, 128 when compared to the viewability ofthe other components of the fixator 100. For example, the markerelements may be constructed of a different material, such as aradio-opaque material, or may be constructed with geometries thatreadily distinguish them from other components of the fixator 100 in theimages 126, 128. In an example embodiment, the marker elements can havedesignated geometries that correspond to their respective locations onthe fixator 100.

Fixator elements can be identified for use in the comparison. Forexample, locations, within the images 126, 128 of fixator elements maybe indicated using the first image information received at operation 318and described in detail above. In some examples, the locations of thefixator elements in the two-dimensional space of the images 126, 128 maybe determined with respect to local origins 125 defined in the imagingplanes of the images 126, 128. The local origins 125 serve as a “zeropoints” for determining the locations of the fixator elements in theimages 126, 128. The locations of the fixator elements can be defined bytheir respective x and y coordinates with respect to a respective localorigin 125. The location of the local origin 125 within the respectiveimage can be arbitrary so long it is in the plane of the image.Typically, the origin is located at the center of the image or at acorner of the image, such as the lower left hand corner. It should beappreciated that the locations of the local origins are not limited toillustrated local origins 125, and that the local origins 125 can bealternatively defined at any other locations.

In some examples, a respective transformation matrix P may then becomputed for each of the images 126, 128. The transformation matricescan be utilized to map location coordinates of one or more respectivefixator elements in actual three-dimensional space to correspondinglocation coordinates of the fixator element(s) in the two-dimensionalspace of the respective image 126, 128. It should be appreciated thatthe same fixator element(s) need not be used in the comparisons of bothimages 126, 128. For example, a fixator element used in constructing thetransformation matrix associated with image 126 can be the same ordifferent from the fixator element used in constructing thetransformation matrix associated with image 128. It should further beappreciated that increasing the number of fixator elements used incomputing the transformation matrices can increase the accuracy method.The following equation represents this operation:

$\begin{matrix}{\begin{bmatrix}x \\y \\1\end{bmatrix} = {P \cdot \begin{bmatrix}X \\Y \\Z \\1\end{bmatrix}}} & (1)\end{matrix}$

The symbols x and y represent location coordinates, with respect to thelocal origin 125, of a fixator element point in the two-dimensionalspace of images 126, 128. The symbols X, Y and Z represent correspondinglocation coordinates, with respect to a space origin 135, of the fixatorelement point in actual three-dimensional space. In the illustratedembodiment, the point corresponding to the center of the plane definedby the upper surface of the upper fixator ring 106 has been designatedas the space origin 135. The illustrated matrix P can be at least fourelements wide and three elements tall. In a preferred embodiment, theelements of the matrix P can be computed by solving the following matrixequation:

A·p=B  (2)

The vector p can contain eleven elements representing values of thematrix P. The following equations present arrangements of the elementsin the vector p and the matrix P:

$\begin{matrix}{p = \lbrack {p_{1}\ p_{2}\ p_{3}\ p_{4}\ p_{5}\ p_{6}\ p_{7}\ p_{8}\ p_{9}\ p_{10}\ p_{11}} \rbrack^{T}} & (3) \\{P = \begin{bmatrix}p_{1} & p_{2} & p_{3} & p_{4} \\p_{5} & p_{6} & p_{7} & p_{8} \\p_{9} & p_{10} & p_{11} & p_{12}\end{bmatrix}} & (4)\end{matrix}$

In the preferred embodiment, the twelfth element p₁₂ of the matrix P canbe set to a numerical value of one. The matrices A and B can beassembled using the two-dimensional and three-dimensional information ofthe fixator elements. For every point representing a respective fixatorelement, two rows of matrices A and B can be constructed. The followingequation presents the values of the two rows added to the matrices A andB for every point of a fixator element (e.g., a center point of arespective universal joint 124):

$\begin{matrix}{{\begin{bmatrix}\ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots \\X & Y & Z & 1 & 0 & 0 & 0 & 0 & {{- x} \cdot X} & {{- x} \cdot Y} & {{- x} \cdot Z} \\0 & 0 & 0 & 0 & X & Y & Z & 1 & {{- y} \cdot X} & {{- y} \cdot Y} & {{- y} \cdot Z} \\\ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots & \ldots\end{bmatrix} \cdot p} = \begin{bmatrix}\ldots \\x \\y \\\ldots\end{bmatrix}} & (5)\end{matrix}$

The symbols X, Y and Z represent location coordinate values of a fixatorelement point in actual three-dimensional space relative to the spaceorigin 135, and the symbols x and y represent location coordinate valuesof the corresponding fixator element point in the two-dimensional spaceof the respective image 126, 128 relative to local origin 125.

For every line representing a respective fixator element, two rows ofmatrices A and B can be constructed. The following equation presents thevalues of the two rows added to the matrices A and B for every line of afixator element (e.g., a center line of a respective adjustable lengthstrut 116):

$\begin{matrix}{\begin{bmatrix}{\begin{matrix}\begin{matrix}\ldots \\{X \cdot a}\end{matrix} \\{{dX} \cdot a} \\\ldots\end{matrix}\begin{matrix}\begin{matrix}\ldots \\{Y \cdot a}\end{matrix} \\{{dY} \cdot a} \\\ldots\end{matrix}\begin{matrix}\begin{matrix}\ldots \\{Z \cdot a}\end{matrix} \\{{dZ} \cdot a} \\\ldots\end{matrix}\begin{matrix}\begin{matrix}\ldots \\a\end{matrix} \\0 \\\ldots\end{matrix}\begin{matrix}\begin{matrix}\ldots \\a\end{matrix} \\{{dX} \cdot b} \\\ldots\end{matrix}\begin{matrix}\begin{matrix}\ldots \\{Y \cdot b}\end{matrix} \\{{dY} \cdot b} \\\ldots\end{matrix}\begin{matrix}\begin{matrix}\ldots \\{Z \cdot b}\end{matrix} \\{{dZ} \cdot b} \\\ldots\end{matrix}} \\\begin{matrix}\ldots & \ldots & \ldots & \ldots \\b & {X \cdot c} & {Y \cdot c} & {Z \cdot c} \\0 & {{dY} \cdot c} & {{dY} \cdot c} & {{dZ} \cdot c} \\\ldots & \ldots & \ldots & \ldots\end{matrix}\end{bmatrix} \cdot {\quad{p = \begin{bmatrix}\ldots \\{- c} \\0 \\\ldots\end{bmatrix}}}} & (6)\end{matrix}$

The symbols X, Y and Z represent location coordinate values of a pointbelonging to a line of a fixator element in actual three-dimensionalspace relative to the space origin 135. The symbols dX, dY and dZrepresent gradient values of the line in actual three-dimensional space.The symbols a, b and c represent constants defining a line in thetwo-dimensional space of a respective image 126, 128. For example, a, b,and c can be computed using two points belonging to a line on arespective image 126, 128. In a preferred embodiment, the value of b isassumed to be 1, unless the line is a vertical line, in which case thevalue of b is zero. A correlation of constants a, b and c with therespective image coordinates x and y is presented in the followingequation:

a·x+b·y+c=0  (7)

The equation (2) can be over constrained by using six or more fixatorelements, for example the adjustable length struts 116. It should beappreciated that it is not necessary for all of the fixator elements tobe visible in a single one of the images 126, 128 in order to obtain thematrix P. It should further be appreciated that if one or more of theabove-described imaging scene parameters are known, the known parameterscan be used to reduce the minimum number of the fixator elementsrequired to constrain equation (2). For instance, such information couldbe obtained from modern imaging systems in DICOM image headers.Preferably, a singular value decomposition or least squares method canbe used to solve equation (2) for values of the vector p.

In some examples, the transformation matrices may then be decomposedinto imaging scene parameters. The following equation can be used torelate the matrix P to matrices E and I:

P=I·E  (8)

It should be appreciated that additional terms can be introduced whendecomposing the matrix P. For example, the method presented by Tsai,described in “A Versatile Camera Calibration Technique for High-Accuracy3D Machine Vision Metrology Using of-the-shelf TV Cameras and Lenses”,IEEE Journal of Robotics & Automation, RA-3, No. 4, 323-344, August1987, which is incorporated herein by reference in its entirety, can beused to correct images 126, 128, for radial distortion.

Matrices E and I contain imaging scene parameters. The followingequation represents a composition of the matrix I:

$\begin{matrix}{I = \begin{bmatrix}{sx} & 0 & {- {tx}} \\0 & {sy} & {{- t}y} \\0 & 0 & {1/f}\end{bmatrix}} & (9)\end{matrix}$

The symbols sx and sy represent values of image coordinate scale factors(e.g., pixel scale factors). The symbol f, representing the focallength, corresponds to the value of the shortest distance between arespective imaging source 130 and the plane of a corresponding image126, 128. The symbols tx and ty represent the coordinates of theprinciple point relative to the local origin 125 of the respective image126, 128. The following equation represents the composition of thematrix E:

$\begin{matrix}{E = \begin{bmatrix}r_{1} & r_{2} & r_{3} & {- ( {{r_{1} \cdot o_{x}} + {r_{2} \cdot o_{y}} + {r_{3} \cdot o_{z}}} )} \\r_{4} & r_{5} & r_{6} & {- ( {{r_{4} \cdot o_{x}} + {r_{5} \cdot o_{y}} + {r_{6} \cdot o_{z}}} )} \\r_{7} & r_{8} & r_{9} & {- ( {{r_{7} \cdot o_{x}} + {r_{8} \cdot o_{y}} + {r_{9} \cdot o_{z}}} )}\end{bmatrix}} & (10)\end{matrix}$

The symbols o_(x), o_(y) and o_(z) represent values of the position ofthe fixator 100 in actual three-dimensional space. The symbols r₁ to r₉describe the orientation of the fixator 100. These values can beassembled into a three-dimensional rotational matrix R represented bythe following equation:

$\begin{matrix}{R = \begin{bmatrix}r_{1} & r_{2} & r_{3} \\r_{4} & r & r_{6} \\r_{7} & r_{8} & r_{9}\end{bmatrix}} & (11)\end{matrix}$

The methods of Trucco and Verri, as described in “IntroductoryTechniques of 3-D Computer Vision”, Prentice Hall, 1998, or the methodof Hartley, as described in “Euclidian Reconstruction from UncalibratedViews”, Applications of Invariance in Computer Vision, pages 237-256,Springer Verlag, Berlin Heidelberg, 1994, which are incorporated hereinin their entireties, can be used to obtain values of the matrices Eand/or I. Utilizing the resulting values of matrices E and I, a completethree-dimensional imaging scene of the fixator 100 and the anatomicalstructure segments 102, 104 can be reconstructed.

For example, FIG. 2 illustrates an example three-dimensional imagingscene reconstructed from the x-ray images 126, 128. In the illustratedembodiment, x-rays are emitted from x-ray imagers 130. It should beappreciated that the x-ray imagers 130 can be the same or differentimagers, as described above. The x-rays emitted from the imagers 130 arereceived on by corresponding imaging devices, thus capturing the images126, 128. Preferably, the positioning of the imagers 130 with respect tothe local origins 125 is known.

In some examples, the images 126, 128 and the imaging scene parametersmay then be used to obtain the positions and/or orientations of theanatomical structure segments 102, 104 in three-dimensional space. Theposition and/or orientation data obtained can be used to develop atreatment plan for a patient, for example to change the orientationand/or position of the fractured first and second anatomical structuresegments 102, 104 in order to promote union between the anatomicalstructure segments 102, 104, as described in more detail below. Itshould be appreciated that the methods and techniques described hereinare not limited to applications of repositioning broken anatomicalstructures, and that orthopedic fixation with imagery analysis can beused in any other type of fixation procedure as desired, for examplelengthening of anatomical structures, correction of anatomical defects,and the like.

In some examples, anatomical structure elements comprisingrepresentations of particular portions (e.g., anatomical features) ofthe anatomical structure segments 102, 104, may then be identified andtheir locations within the images 126, 128 determined. For example,locations, within the images 126, 128 of the first and the secondanatomical structure segments may be indicated using the second imageinformation received at operation 320 and described in detail above. Insome examples, the locations of the anatomical structure elements may bedetermined with respect to the respective local origins 125 of images126, 128.

The anatomical structure elements can be used in the construction of thethree-dimensional representation of the position and/or orientation ofthe anatomical structure segments 102, 104. Preferably, the anatomicalstructure elements are easy to identify in the images 126, 128. Points,lines, conics, or the like, or any combination thereof can be used todescribe the respective geometries of the anatomical structure elements.For example, in the illustrated embodiment, points 134 and 136representing the fractured ends 103, 105 of the anatomical structuresegments 102, 104, respectively, are identified as anatomical structureelements in the images 126, 128.

The anatomical structure elements can further include marker elementsthat are implanted into the anatomical structure segments 102, 104 priorto imaging. The marker elements can be used as a supplement to or inlieu of the above-described anatomical structure elements identified inthe images 126, 128. The marker elements can be configured for enhancedviewability in the images 126, 128 when compared to the viewability ofanatomical features of the anatomical structure segments 102, 104. Forexample, the marker elements may be constructed of a radio-opaquematerial, or may be constructed with readily distinguishable geometries.

A three-dimensional representation 200 of the anatomical structuresegments 102, 104 can be reconstructed. The three-dimensionalrepresentation can be constructed with or without a correspondingrepresentation of the fixator 100. In the illustrated embodiment, pairsof ray-lines, such as ray lines 138, 140 and 142, 144 can be constructedfor the anatomical structure element points 134, 136, respectively. Eachray line connects an anatomical structure element in one of the images126, 128 with a respective imager 130. Each pair of ray lines can beanalyzed for a common intersection point, such as points 146, 148. Thecommon intersection points 146, 148 represent the respective positionsof the anatomical structure element points 134, 136, in thethree-dimensional representation of the anatomical structure segments102, 104. Of course more than a pair of ray lines, such as a plurality,can be constructed, for example if more than two images were captured.If the ray lines of a particular set do not intersect, a point closestto all the ray lines in the set can be used as the common intersectionpoint.

The positions and/or orientations of the anatomical structure segments102, 104 can be quantified or measured using common intersection points,for instance points 146, 148. For example, lines representing centerlines of the anatomical structure segments 102, 104 can be constructedand can be compared to the anatomical axes of the patient. Additionally,the distance between the fractured ends 103, 105 of the anatomicalstructure segments 102, 104 can be quantified. Using these or similartechniques, the positions and/or orientations of the anatomicalstructure segments 102, 104 can be determined. It is further noted that,in some examples, in addition to the positions and orientations of thefirst and second anatomical structure segments, the positions andorientation of rings (and/or other elements of the fixation apparatus)in three-dimensional space may also be determined, for example using anyof the techniques described. For example, in some cases, locations ofthe rings within the images 126, 128 may be determined based on thefirst image information and/or other provided information. In someexamples, these locations may then be used to determine the positionsand orientations of the rings in three-dimensional space. Additionally,in some examples, configuration information for the fixation apparatus,such as ring diameters and strut length and mounting information, mayalso be used to determine positions and orientations of the rings inthree-dimensional space.

Referring now to FIG. 3B, at operation 324, one or more deformityparameters are calculated. The deformity parameters may includeparameters relating to the deformity associated with the first andsecond anatomical structure segments. For example, in some cases, thedeformity parameters may include an amount of translation (e.g.,lateral, medial, anterior, and/or posterior), a degree of coronalangulation (e.g., valgus and/or varus), a degree of sagittal angulation,an amount by which anatomical structure length is too short and/or toolong, a degree of clinical rotational deformity (e.g., internal and/orexternal), and others. In some examples, the deformity parameters may becalculated as part of the process determining the positions andorientations of the first and segment anatomical structure segmentsdescribed above at operation 422, for example using the techniquesdescribed above with reference to operation 422.

At operation 326, the deformity parameters calculated at operation 424are displayed, for example using one or more graphical user interfacesof a computing system. Referring now to FIG. 9, a deformity parameterinterface 900 is shown. As shown, interface 900 includes various fields901-906 for displaying calculated values of various example deformityparameters, including AP View translation and coronal angulation, LATView translation and sagittal angulation, an amount by which anatomicalstructure length is too short or too long, and a degree of clinicalrotational deformity. In the example of FIG. 9, fields 901-905 each havea respective PFM badge 915 (including the text “PFM”) that is displayedto the left of each field 901-905. Each PFM badge 915 indicates that thevalue shown in the respective field 901-905 has been calculated by thesoftware. Interface 900 allows the deformity parameter values that aredisplayed in each field 901-906 to be edited by a user, for example bytyping a number in the fields 901-906 and/or by using number incrementcontrols 916 displayed to the right of each field 901-906. When a useredits a value that was calculated by the software, the PFM badge 915adjacent to the respective field may be removed to indicate that thevalue for the field has been edited by the user. In some examples, afterediting the values in one or more fields, the user may select RefreshPerspective Frame Matching Data button 920 to return each of the fieldsto the value that was calculated by the software. Also, in someexamples, after editing the values in one or more fields, the user mayselect Save and Update button 921 to cause the deformity parameters tobe recalculated based on the edited values provided by the user, forexample by repeating all or any portion of the calculations performed atoperation 322.

At operation 328, a graphical representation of the position andorientation of the first and the second anatomical structure segments isgenerated and displayed. The graphical representation of the positionand orientation of the first and the second anatomical structuresegments may be displayed using one or more graphical user interfaces ofa computing system. For example, as shown in FIG. 9, interface 900includes a graphical representation 950 of the position and orientationof the first and the second anatomical structure segments. Graphicalrepresentation 950 includes a representation 931 of the proximalanatomical structure segment and a representation 932 of the distalanatomical structure segment. In some examples, the graphicalrepresentation 950 may be generated based, at least in part, on thepositions and orientations of the first and segment anatomical structuresegments determined at operation 322. In some examples, when the useredits one or more deformity parameters and selects Save and Updatebutton 921, the graphical representation 950 may also be adjusted toreflect the saved edits to the deformity parameters. Graphicalrepresentation 950 may, for example, improve efficiency and reliabilityby providing the user with a visual confirmation of information enteredinto interface 900, for example to allow fast and easy identification oferrors or other problems.

At operation 330, one or more mounting parameters are calculated. Themounting parameters may include parameters relating to mounting of areference ring of the fixator onto a respective anatomical structuresegment. For example, in some cases, the mounting parameters may includean amount of offset (e.g., lateral, medial, anterior, and/or posterior)such as for a center of the reference ring with respect to a referencepoint, a degree of tilt (e.g., proximal and/or distal), an amount ofaxial offset, a master tab rotation, and others. In some examples, themounting parameters may be calculated as part of the process determiningthe positions and orientations of the first and segment anatomicalstructure segments described above at operation 322, for example usingthe techniques described above with reference to operation 322. It isnoted that, for the process of FIG. 3, the reference ring is notnecessarily required to be orthogonal with respect to the respectiveanatomical structure segment on which it is mounted. Thus, in someexamples, the reference ring may be non-orthogonal with respect to therespective anatomical structure segment on which it is mounted.

At operation 432, the mounting parameters calculated at operation 430are displayed, for example using one or more graphical user interfacesof a computing system. Referring now to FIG. 10, a mounting parameterinterface 1000 is shown. As shown, interface 1000 includes variousfields 1001-1006 for displaying calculated values of various examplemounting parameters, including AP View offset and tilt, LAT View offsetand tilt, axial offset, and master tab rotation. In the example of FIG.10, fields 1001-1006 each have a respective PFM badge 1015 that isdisplayed to the left of each field 1001-1006. Each PFM badge 1015indicates that the value shown in the respective field 1001-1006 hasbeen calculated by the software. Interface 1000 allows the mountingparameter values that are displayed in each field 1001-1006 to be editedby a user, for example by typing a number in the fields 1001-1006 and/orby using number increment controls 1016 displayed to the right of eachfield 1001-1006. When a user edits a value that was calculated by thesoftware, the PFM badge 1015 adjacent to the respective field may beremoved to indicate that the value for the field has been edited by theuser. In some examples, after editing the values in one or more fields,the user may select Refresh Perspective Frame Matching Data button 1020to return each of the fields to the value that was calculated by thesoftware. Also, in some examples, after editing the values in one ormore fields, the user may select Save and Update button 1021 to causethe deformity parameters to be recalculated based on the edited valuesprovided by the user, for example by repeating all or any portion of thecalculations performed at operation 322.

At operation 334, a graphical representation of the position andorientation of the reference ring and the respective anatomicalstructure segment to which it is mounted is generated and displayed. Thegraphical representation of the position and orientation of thereference ring and the respective anatomical structure segment may bedisplayed using one or more graphical user interfaces of a computingsystem. For example, as shown in FIG. 10, interface 1000 includes agraphical representation 1050 of the position and orientation of thereference ring and the respective anatomical structure segment.Graphical representation 1050 includes a representation 1031 of theproximal anatomical structure segment, a representation 1033 of theproximal (reference) ring, and a representation 1032 of the distalanatomical structure segment. In some examples, the graphicalrepresentation 1050 may be generated based, at least in part, on thepositions and orientations of the reference ring and the respectiveanatomical structure segment determined at operation 322. The graphicalrepresentation of the reference ring and the respective anatomicalstructure segment may, therefore, reflect and/or indicate the positionsand orientations of reference ring and the respective anatomicalstructure segment determined at operation 322. In some examples, whenthe user edits one or more mounting parameters and selects Save andUpdate button 1021, the graphical representation 1050 may also beadjusted to reflect the saved edits to the mounting parameters.Graphical representation 1050 may, for example, improve efficiency andreliability by providing the user with a visual confirmation ofinformation entered into interface 1000, for example to allow fast andeasy identification of errors or other problems.

At operation 336, one or more treatment plan options are received, forexample using one or more graphical user interfaces of a computingsystem. A treatment plan is a plan for manipulating the fixationapparatus, for example in order to correct the deformity of the firstand the second anatomical structure segments. The treatment plan mayinclude, for example, a plan for making gradual adjustments to thepositions and orientations of the fixator rings with respect to eachother, for example by changing the lengths of the struts of the fixationapparatus. Referring now to FIG. 11, an example treatment plan interface1100A is shown. The interface 1100A includes controls for selecting, bya user, various treatment plan options. In particular, controls 1101and/or 1102 allow selecting of a treatment plan start date, control 1103allows selection of an option to perform axial movement first (e.g., inan initial part of the treatment, such as prior to rotational movement),control 1104 allows selection of an option to indicate a final distancebetween reference points, control 1105 allows selection of an option tocalculate the treatment plan based on a specified duration (e.g., anumber of days) for axial movement, control 1106 allows selection of anoption to calculate the treatment plan based on a rate of distraction atthe reference point (e.g., for example millimeters (mm)/day) for axialmovement, control 1108 allows selection of an option to calculate thetreatment plan based on a specified duration (e.g., a number of days)for deformity correction, control 1109 allows selection of an option tocalculate the treatment plan based on a rate of distraction at thereference point (e.g., for example millimeters (mm)/day) for deformitycorrection, and control 1107 allows selection of an option to performtwo adjustments per day. In some examples, when control 1007 is notselected, a default option of one adjustment per day may be used. Insome examples, after selecting desired treatment plan options, the usermay select Update Adjustment Plan button 1110 to trigger generation ofthe treatment plan. Additionally, after initial generation of thetreatment plan, the user may also be permitted to adjust the treatmentplan options and have the treatment plan re-generated with the adjustedoptions by re-selecting Update Adjustment Plan button 1110

At operation 338, manipulations to the fixation apparatus for correctionof the anatomical structure deformity (i.e., a treatment plan) aredetermined. The manipulations to the fixation apparatus may includeadjustments to the struts of the fixation apparatus, such as adjustmentsto the sizes and/or lengths of the struts. In some examples, operation338 may be performed based, at least in part, on the treatment planoptions received at operation 336. For example, operation 338 may beperformed based, at least in part, on specified start date, oninstructions to perform axial movement first (e.g., in an initial partof the treatment, such as prior to rotational movement), a specifiedfinal distance between reference points, instructions to performadditional lengthening by a specified amount, instructions to generatean axial gap to ensure anatomical structure clearance, a specifiedduration (e.g., a number of days) of treatment, a specified rate ofdistraction, and/or instructions to perform two perform a specifiedquantity (e.g., one, two, etc.) of adjustments per day.

In some examples, the treatment plan may also be determined based, atleast in part, on a determination of desired changes to the positionsand/or orientations of the anatomical structure segments 102, 104, forinstance how the anatomical structure segments 102, 104 can berepositioned with respect to each other in order to promote unionbetween the anatomical structure segments 102, 104. For example, in somecases, it may be desirable to change the angulation of the secondanatomical structure segment 104 such that the axes L1 and L2 arebrought into alignment, and to change the position of the secondanatomical structure segment such that the fractured ends 103, 105 ofthe anatomical structure segments 102, 104 abut each other. Once thedesired changes to the positions and/or orientations of the anatomicalstructure segments 102, 104 have been determined, a treatment plan foreffecting the position and/or orientation changes can be determined. Ina preferred embodiment, the desired changes to the positions and/ororientations of the anatomical structure segments 102, 104 can beeffected gradually, in a series of smaller changes. The positions and/ororientations of the anatomical structure segments 102, 104 can bechanged by changing the positions and/or orientations of the upper andlower fixator rings 106, 108 with respect to each other, for instance bylengthening or shortening one or more of the length adjustable struts116.

The required changes to the geometry of the fixator 100 (i.e., theposition and/or orientation of the fixator 100) that can enable thedesired changes to the positions and/or orientations of the anatomicalstructure segments 102, 104 can be computed using the matrix algebradescribed above. For example, the required repositioning and/orreorientation of the second anatomical structure segment 104 withrespect to the first anatomical structure segment 102 can be translatedto changes in the position and/or orientation of the lower fixator ring108 with respect to the upper fixator ring 106.

At operation 340, indications of the determined manipulations to thefixation apparatus are provided to one or more users. For example, insome cases, indications of the determined manipulations to the fixationapparatus may be provided using one or more graphical user interfaces ofa computing system, using a printed hard copy, using audio feedback,and/or using other techniques. In particular, referring now to FIG. 12,it is seen that indications of the determined manipulations to thefixation apparatus may be provided within interface 1100B. Specifically,selection of Strut Adjustment Plan tab 1122 may cause treatment planinterface 1100B to provide a chart 1130, including day-by-daymanipulation information for each strut within the fixation apparatus.In this example, chart 1130 shows a length for each strut on each day oftreatment. In some examples, one or more alerts may be generated for oneor more manipulations to the fixation apparatus that result in at leastone of strut movement of more than a threshold amount. For example, insome cases, strut movements exceeding particular threshold amount (e.g.,3 mm per day), which may be referred to as rapid strut movements, may beindicated by displaying a red triangle icon next to the indication ofthe strut movement in chart 1130. As also shown in FIG. 12, a PDFversion of the chart 1130 may be generated by selecting View Draft PDFbutton 1131. The generated PDF may, in some examples, be printed tocreate a hard copy version of chart 1130.

In the example of FIG. 12, chart 1130 includes blocks 1132-A and 1132-Bindicating ranges of dates on which changes of strut sizes, referred toas strut swaps, may be performed. In particular, block 1132-A indicatesthat a strut swap may be performed for Strut 4 on Day 0 through Day 2,while block 1132-B indicates that a strut swap may be performed forStrut 4 on Day 3 through Day 14 (and subsequent days). In some examples,blocks 1132-A and 1132-B may be color-coded to match a color assigned toa respective strut. For example, blocks 1132-A and 1132-B may be coloredgreen to match a green color that may be assigned to Strut 4. Referringnow to FIG. 13, Strut Swaps Calendar tab 1123 of treatment planinterface 1100-C may be selected to generate a calendar 1140 indicatingranges of dates on which strut swaps may be performed.

In some examples, the struts of the fixation apparatus attached to thepatient may be color-coded, for example using color-coded caps, marker,or other color-coded materials included within and/or attached to thestruts. In some examples, the physical color-coding of the struts in thefixation apparatus attached to the patient may match the color-coding ofstruts used in the software. For example, the physical color-coding ofthe struts in the fixation apparatus may match the color-coding ofstruts that may be used to color-code the blocks 1132-A and 1132-B ofchart 1130, graphical representation 520, and other color-codedrepresentations of the struts displayed by the software. In someexamples, this may make it easier for physicians and/or patients toconfirm that, when they physically adjust a strut on the fixationapparatus, they are adjusting the correct strut by the correct amount.

At operation 342, one or more graphical representations of the positionand orientation of the first and second anatomical structure segmentsand the rings of the fixation apparatus is generated and displayed. Thegraphical representation of the position and orientation of the firstand the second anatomical structure segments and the rings of thefixation apparatus may be displayed using one or more graphical userinterfaces of a computing system. For example, referring back to FIG.11, selection of Treatment Simulation tab 1121 may cause interface 1100to display a graphical representation 1150 of the position andorientation of the first and the second anatomical structure segmentsand the rings of the fixation apparatus. Graphical representation 1150includes a representation 1031 of the proximal anatomical structuresegment, a representation 1033 of the proximal (reference) ring, arepresentation 1032 of the distal anatomical structure segment, and arepresentation 1034 of the distal ring. In some examples, the one ormore graphical representations of the position and orientation of thefirst and second anatomical structure segments and the rings of thefixation apparatus may include day-by-day graphical representations ofthe position and orientation of the first and second anatomicalstructure segments and the rings of the fixation apparatus throughouttreatment for the anatomical structure deformity. For example, as shownin FIG. 11, a user may select a particular day of treatment for which togenerate and display a graphical representation 1150 using controls1151, 1152, 1153, and/or 1154. For example, control 1151 may be selectedto allow incrementing of the selected day, control 1154 may be selectedto allow decrementing of the selected day, and slider 1152 may be slidalong bar 1153 to increment and/or decrement the selected day. It isalso noted that slider 1152 displays an indication of the currentlyselected day, which, in the example of FIG. 11, is treatment day zero.Thus, in FIG. 11, graphical representation 1150 shows the position andorientation of the first and second anatomical structure segments andthe rings of the fixation apparatus at treatment day zero. Usingcontrols 1151-1154 to select a different day of treatment may causegraphical representation 1150 to be adjusted to show the position andorientation of the first and second anatomical structure segments andthe rings of the fixation apparatus on the selected different day. Asshould be appreciated, allowing the surgeon and/or patient to seegraphical representations of the position and orientation of the firstand second anatomical structure segments and the rings of the fixationapparatus throughout treatment may be beneficial by, for example,providing an additional visual tool to improve accuracy and assist inplanning of treatment. Additionally, graphical representation 1150 (aswell as graphical representations described herein) may, for example,improve efficiency and reliability by providing the user with a visualconfirmation of information entered into interface 1100, for example toallow fast and easy identification of errors or other problems. It isfurther noted that the view of graphical representation 1150 (as well asother graphical representations described herein) may be rotated (forexample by a complete 360 degrees), zoomed in and out, moved indirection, and otherwise manipulated, for example using controls1181-1184 adjacent to the upper right side of the graphicalrepresentation 1150. This may allow views of the first and secondanatomical structure segments and/or the rings of the fixation apparatusfrom various orientations that may not be available, or may be difficultto obtain, using x-rays and other imaging techniques, thereby alsoimproving reliability and accuracy and providing additional visualconfirmation of calculated values. In particular, view of the graphicalrepresentation 1150 may be rotated using control 1181, zoomed in usingcontrol 1182, zoomed out using control 1183, and panned using control1184. Also, in some examples, other controls, such as a mouse andtouchscreen, may also be employed to rotate, zoom, pan, and otherwisemanipulate graphical representation 1150. Additionally, in someexamples, control 1185 may be used to select an anteroposterior (AP)view, control 1186 may be used to select a lateral view, and control1187 may be used to select a proximal view.

At operation 344, the treatment plan may be implemented, that is thegeometry of the fixation apparatus may be changed, for example based onthe manipulations determined at operation 338, in order to changepositions and orientations of the anatomical structure segments.

Strut Swap Range Indications

As described above, manipulations to a fixator for correction of ananatomical structure deformity (i.e., a treatment plan) may bedetermined and implemented. The manipulations to the fixator may includeadjustments to the struts of the fixator, such as adjustments to thesizes and/or lengths of the struts. In particular, the manipulations tothe fixator may include one or more strut swaps, which is a swap (i.e.,exchange) of a replaced strut for a different sized replacement strut byremoving the replaced strut from the fixator and replacing it with thereplacement strut. A fixator strut is typically capable of beingadjusted in size throughout a respective length range, such as from amaximum length to a minimum length. Different sized fixator struts(e.g., large, medium, small) typically have different respective lengthranges. Strut swaps may be performed when the treatment plan indicatesthat the length of the replaced strut is to be reduced to a length thatis shorter than a minimum length of the replaced strut—or that thelength of the replaced strut is to be increased to a length that alonger than a maximum length of the replaced strut. In some examples,the length ranges of adjacent strut sizes may overlap one another withan overlapping length range (typically 10 millimeters (mm)). Forexample, in some cases, the minimum length of a medium strut may be 10mm shorter than the maximum length of a small strut. This overlappingstrut range may allow patients to have range of time in which they mayperform a strut swap, referred to as a strut swap range. Longer strutswap ranges (e.g., strut swap ranges of several days) may sometimes bebeneficial to patients by allowing them greater flexibility in decidingwhen to perform a particular strut swap.

In some examples, the software may provide three-dimensional day-by-daygraphical representations that show the fixator and the anatomicalstructure segments throughout the course of treatment for the anatomicalstructure deformity. Described herein are techniques for indicating,within the three-dimensional day-by-day graphical representations, astrut swap range within which a strut swap may be performed. In someexamples, these indications may graphically indicate a particular struton which the strut swap may be performed and may also indicate amounts(e.g., percentages) of time that are remaining and/or elapsed within inthe strut swap range.

Referring now to FIG. 14, an example process for providing a pluralityof fixator graphical representations including graphical strut swaprange indications will now be described in detail. In particular, theprocess of FIG. 14 is initiated at operation 1410, at whichmanipulations to a fixator for correction of a deformity of first andsecond anatomical structure segments are determined by a computingsystem. The fixator may include rings and struts. The manipulations mayinclude a plurality of adjustments to strut lengths and a strut swapfrom a replaced strut to a replacement strut. The manipulations areperformed throughout a set of stages, such as any number of days. Thus,in some examples, each stage in the set of stages may be a respectiveday. A number of example techniques for determining manipulations to afixator for correcting an anatomical structure deformity are describedin detail above (such as with respect to operation 338 of FIG. 3B andbased on operations 310-336 of FIGS. 3A-3B) and are not repeated here.

At operation 1412, a strut swap range in which the strut swap isperformable is determined by the computing system. The strut swap rangecomprises a sub-set of stages within the set of stages. For example, thestrut swap range may include a particular sub-set of consecutive dayswithin the total set of days over which the treatment plan isimplemented. The sub-set of stages may include a swap start stage. Theswap start stage is the stage at which the strut swap range starts, suchas an initial day of the strut swap range (i.e., the initial day onwhich the strut swap may be performed). The sub-set of stages may alsoinclude a swap end stage. The swap end stage is the stage at which thestrut swap range ends, such as a final day of the strut swap range(i.e., the final day on which the strut swap may be performed). Thesub-set of stages may also include one or more intermediate stagesbetween the swap start stage and the swap end stage, such as one or moredays in between the initial day of the strut swap range and the finalday of the strut swap range. The software may determine a strut swaprange based on the calculated strut length adjustments in the treatmentplan (e.g., as described at operation 334 of FIG. 3B)—and also based onthe length ranges of available struts, which may be input to orotherwise made available to the software.

At operation 1414, the plurality of fixator graphical representationsare generated by the computing system. The plurality of fixatorgraphical representations may be displayed in a graphical user interface(GUI) of a computing system. The plurality of fixator graphicalrepresentations may be three-dimensional graphical representations ofthe fixator, such as including three-dimensional graphicalrepresentations of the rings and struts of the fixator andthree-dimensional graphical representations of the first and the secondanatomical structure segments to which the fixator is attached. In someexamples, the plurality of fixator graphical representations may includestage-by-stage (e.g., day-by-day) graphical representations of thefixator throughout the course of the treatment plan.

The plurality of fixator graphical representations may include a swapstart fixator graphical representation, a swap end fixator graphicalrepresentation, and one or more intermediate fixator graphicalrepresentations. The swap start fixator graphical representation mayrepresent the fixator at the swap start stage. The swap end fixatorgraphical representation may represent the fixator at the swap endstage. The one or more intermediate fixator graphical representationsmay represent the fixator at the one or more intermediate stages betweenthe swap start stage and the swap end stage.

Each of the plurality of fixator graphical representations may include arespective one of a plurality of replaced strut graphicalrepresentations and a respective one of a plurality of replacement strutgraphical representations. The plurality of replaced strut graphicalrepresentations may change from a first rendering state in the swapstart fixator graphical representation to a second rendering state inthe swap end fixator graphical representation. By contrast, theplurality of replacement strut graphical representations may change fromthe second rendering state in the swap start fixator graphicalrepresentation to the first rendering state in the swap end fixatorgraphical representation.

In some examples, the first rendering state may be a more opaque stateand the second rendering state may be a less opaque state that is lessopaque (e.g., more transparent) than the more opaque state. In someexamples, the first rendering state may be a mostly opaque state, andthe second rendering state may be a mostly transparent state.Additionally, in some examples, the plurality of replaced strutgraphical representations and the plurality of replacement strutgraphical representations may have linear rates of change between thefirst rendering state and the second rendering state. In some cases, theone or more intermediate fixator graphical representations may berendered according to the linear rates of change. Thus, in someexamples, the replaced strut graphical representations may graduallyfade out from the swap start stage to swap end stage, while thereplacement strut graphical representations may gradually fade in fromthe swap start stage to swap end stage.

Referring now to FIGS. 15-21, some examples of graphical strut swaprange indications will now be described in detail. Specifically, FIG. 15depicts an interface 1500, such as a graphical user interface (GUI) of acomputing system, that includes an example fixator graphicalrepresentation 1510 at a first stage (in this example Day 0) of atreatment plan. The graphical representation 1510 includes six strutgraphical representations 1511-1516 and ring graphical representations1517 and 1518. The interface 1500 also includes anatomical structuregraphical representations 1551 and 1552. The fixator graphicalrepresentation 1510 and the anatomical structure graphicalrepresentations 1551 and 1552 are three-dimensional graphicalrepresentations that show positions and orientations of the fixatorelements (e.g., rings and struts) and the anatomical structure segmentsin three-dimensional space. The interface 1500 further includes a slidebar 1560 and slider 1561 that can be used to select a desired treatmentstage (e.g., day) for which to view a respective fixator graphicalrepresentation. In FIG. 15, the slider 1561 is placed at the start(i.e., left edge) of the slide bar 1560 to select an initial treatmentstage (Day 0). In this example, on Day 0 of treatment, none of thestruts are currently within a strut swap range.

Referring now to FIG. 16, an example is shown in which a replaced strut(represented by strut graphical representation 1511) enters into a strutswap range. In particular, as shown in FIG. 16, a user has moved slider1561 to the right to switch from a first treatment stage (Day 0) to asecond treatment stage (Day 1). Accordingly, a respective fixatorgraphical representation 1610 corresponding to Day 1 is shown in FIG.16. In this example, fixator graphical representation 1610 is a swapstart graphical representation that represents the start of a strut swaprange for a replaced strut (represented by strut graphicalrepresentation 1511). Specifically, the start of the strut swap range isindicated by displaying strut graphical representation 1511(corresponding to the replaced strut) using a first rendering state,which in this example is a more opaque state. Additionally, FIG. 16displays a strut graphical representation 1611 corresponding to areplacement strut for which the replaced strut is exchanged during thestrut swap range. The start of the strut swap range is further indicatedby displaying strut graphical representation 1611 (corresponding to thereplacement strut) using a second rendering state, which in this exampleis a less opaque state. As shown, the less opaque state of replacementstrut graphical representation 1611 is less opaque (e.g., moretransparent) than the more opaque state of replaced strut graphicalrepresentation 1511.

In this example, the strut swap range extends from Day 1 (the swap startstage) to Day 5 (the swap end stage). Thus, Days 2-4 are intermediatestages between the swap start stage and the swap end stage. Accordingly,in this example, the strut swap range indication includes six graphicaltransitions from 100% opaque to 0% opaque (fully transparent) and viceversa. In this example, the replaced strut graphical representation 1511and the replacement strut graphical representation 1611 have linearrates of change. Accordingly, for each day of the strut swap range, thereplaced strut representation 1511 and the replacement strut graphicalrepresentation 1611 are rendered with a 16.66% increase or decrease inopacity from the prior day (corresponding to 100% divided by the sixgraphical transitions). Thus, in this example, the first rendering state(e.g., more opaque state) that is used for the replaced strut graphicalrepresentation 1511 in FIG. 16 (and later used for the replacement strutgraphical representation 1611 in FIG. 20) corresponds to a state of83.32% opacity (i.e., 100%−16.66%). Additionally, in this example, thesecond rendering state (e.g., less opaque state) that is used for thereplacement strut graphical representation 1611 in FIG. 16 (and laterused for the replaced strut graphical representation 1511 in FIG. 20)corresponds to a state of 16.66% opacity (i.e., 0%+16.66%).

Referring now to FIG. 17, a fixator graphical representation for a thirdtreatment stage (Day 2) is shown. In particular, as shown in FIG. 17, auser has moved slider 1561 further to the right to switch from Day 1 toDay 2. Accordingly, a respective fixator graphical representation 1710corresponding to Day 2 is shown in FIG. 17. In this example, Day 2 isthe second of five days from the start to the end of the strut swaprange. In this example, the replaced strut graphical representation 1511and the replacement strut graphical representation 1611 have linearrates of change between the first rendering state and the secondrendering state. This is indicated by displaying replaced strutgraphical representation 1511 in fixator graphical representation 1710using an intermediate rendering state that represents a state of 66.66%opacity, which is a decrease of 16.66% from the rendering state of83.32% opacity of replaced strut graphical representation 1511 in FIG.16. Additionally, replacement strut graphical representation 1611 isdisplayed in fixator graphical representation 1710 using an intermediaterendering state that represents a state of 33.33% opacity, which is anincrease of 16.66% from the rendering state of 16.66% opacity ofreplacement strut graphical representation 1611 in FIG. 16. Thus, inFIG. 17, the replaced strut graphical representation 1511 is still moreopaque than the replacement strut graphical representation 1611, but thecontrast (i.e., difference in opacity) is not as much as in FIG. 16.

Day 3 is a midpoint stage halfway between the swap start stage and theswap end stage. Referring now to FIG. 18, a fixator graphicalrepresentation for a fourth treatment stage (Day 3) is shown. Inparticular, as shown in FIG. 18, a user has moved slider 1561 further tothe right to switch from to switch from Day 2 to Day 3. Accordingly, arespective fixator graphical representation 1810 corresponding to Day 3is shown in FIG. 18. In this example, Day 3 is the third of five daysfrom the start to the end of the strut swap range. Thus, Day 3 is fiftypercent of the elapsed time period (i.e., halfway) from the swap startstage to the swap end stage. This is indicated by displaying bothreplaced strut graphical representation 1511 and replacement strutgraphical representation 1611 in fixator graphical representation 1810using an intermediate rendering state of 50% opacity. Thus, in FIG. 18,the replaced strut graphical representation 1511 and the replacementstrut graphical representation 1611 have the same level of opacity toindicate that Day 3 is the midpoint of the strut swap range.

Referring now to FIG. 19, a fixator graphical representation for a fifthtreatment stage (Day 4) is shown. In particular, as shown in FIG. 19, auser has moved slider 1561 further to the right to switch from Day 3 toDay 4. Accordingly, a respective fixator graphical representation 1910corresponding to Day 4 is shown in FIG. 19. In this example, Day 4 isthe fourth of five days from the start to the end of the strut swaprange. This is indicated by displaying replaced strut graphicalrepresentation 1511 in fixator graphical representation 1910 using anintermediate rendering state of 33.33% opacity, which is a decrease of16.66% from the rendering state of 50% opacity of replaced strutgraphical representation 1511 in FIG. 18. Additionally, replacementstrut graphical representation 1611 is displayed in fixator graphicalrepresentation 1710 using an intermediate rendering state of 66.66%opacity, which is an increase of 16.66% from the rendering state of 50%opacity of replacement strut graphical representation 1611 in FIG. 18.Thus, in FIG. 19, the replaced strut graphical representation 1511 isnow less opaque than the replacement strut graphical representation1611, thereby indicating that the strut swap range is more than halfwayelapsed.

Referring now to FIG. 20, a fixator graphical representation for a sixthtreatment stage (Day 5) is shown. In particular, as shown in FIG. 20, auser has moved slider 1561 further to the right to switch from Day 4 toDay 5. Accordingly, a respective fixator graphical representation 2010corresponding to Day 5 is shown in FIG. 20. In this example, fixatorgraphical representation 2010 is a swap end fixator graphicalrepresentation that represents the end of the strut swap range.Specifically, the end of the strut swap range is indicated by displayingreplaced strut graphical representation 1511 using the second renderingstate, which in this example is a less opaque state (e.g., 16.66%opacity). Thus, replaced strut graphical representation 1511 is shown inFIG. 20 (for the swap end stage) with the same level opacity (16.66%opacity) used for the replacement strut graphical representation 1611 inFIG. 16 (for the swap start stage). Additionally, FIG. 20 displaysreplacement strut graphical representation 1611 using the firstrendering state, which in this example is the more opaque state (e.g.,83.32% opacity). Thus, replacement strut graphical representation 1611is shown in FIG. 20 (for the swap end stage) with the same level opacity(83.32% opacity) used for the replaced strut graphical representation1511 in FIG. 16 (for the swap start stage). Accordingly, it can be seenthat, at the start of strut swap range (FIG. 16), the replaced strutgraphical representation is shown as mostly opaque and then graduallyfades out over the course of the strut swap range until it is mostlytransparent at the end of the strut swap range (FIG. 20). By contrast,at the start of strut swap range (FIG. 16), the replacement strutgraphical representation is shown as mostly transparent and thengradually fades in over the course of the strut swap range until it ismostly opaque at the end of the strut swap range (FIG. 20). In thismanner, fixator graphical representations 1610-2010 may provide visualindications of a particular strut that is in a swap range—and visualindications of an amount (e.g., percentage) of time that has elapsedand/or that remains in the strut swap range.

Referring now to FIG. 21, a fixator graphical representation for aseventh treatment stage (Day 6) is shown. In particular, as shown inFIG. 21, a user has moved slider 1561 further to the right to switchfrom Day 5 to Day 6. Accordingly, a respective fixator graphicalrepresentation 2110 corresponding to Day 6 is shown in FIG. 21. In thisexample, fixator graphical representation 2110 represents the fixatorafter conclusion of the strut swap range. As shown, the replaced strutgraphical representation 1511 is no longer shown and has instead beenreplaced by replacement strut graphical representation 1611 within thefixator graphical representation 2110.

Interfamily Strut Swaps

In some examples, there may be various different strut families that maybe available for use with a fixator. A family of struts, as that term isused herein, is a group of struts of different sizes (e.g., small,medium, large, etc.) whose length may be adjusted using a common lengthadjustment technique. Different strut families may therefore havedifferent length adjustment techniques with respect to one another. Twoexample strut families are a standard strut family and a quick adjuststrut family. In some examples, standard struts may have their lengthsadjusted by turning a locking collar until it is out of the way, andthen turning a length adjustment knob until a length indicator is inline with a planned length. At that point, the locking collar may bereturned to be in firm direct contact with the adjustment knob withoutallowing either of them to twist. By contrast, in some examples, quickadjust struts may have their lengths adjusted by pushing in on anadjustment knob and turning until a click is heard. The adjustment knobmay be turned as many times as needed to get the length indicator inline with the planned length. In some examples, the quick adjust strutsmay be adjusted in a quick and efficient fashion and may reduceinadvertent strut movements.

One limitation of at least some conventional software applications inthis field is that the software may be limited to generating treatmentplans that include only intrafamily strut swaps (i.e., swaps within asingle strut family) as opposed to interfamily strut swaps (i.e., swapsbetween different strut families). One disadvantage of this limitationis that the strut lengths of different families may differ from oneanother. In some examples, the maximum length of a longest strut in onefamily may be longer than the maximum length of a longest strut in adifferent family. Additionally, the minimum length of a shortest strutin one family may be shorter than the minimum length of a shortest strutin a different family.

For example, consider a scenario in which a maximum length of a longestquick adjust strut is longer than a maximum length of a longest standardstrut. Now suppose that there is a clinical case in which standardstruts are selected for use. Also suppose that, for completion, theclinical case requires a particular strut length that is longer than themaximum length of the longest standard strut but that could be completedusing the longest quick adjust strut. In this example, conventionalsoftware techniques that allow only intrafamily strut swaps may notallow a swap from a standard strut to the longest quick adjust strut inorder to achieve the longer strut length.

As another example, consider a scenario in which a minimum length of ashortest standard strut is shorter than a minimum length of a shortestquick adjust strut. Now suppose that there is a clinical case in whichquick adjust struts are selected for use. Also suppose that, forcompletion, the clinical case requires a particular strut length that isshorter than the minimum length of the shortest quick adjust strut butthat could be completed using the shortest standard strut. In thisexample, conventional software techniques that allow only intrafamilystrut swaps may not allow a swap from a quick adjust strut to theshortest standard strut in order to achieve the shorter strut length.

In order to alleviate the above and other problems, techniques aredescribed herein in which a treatment plan may be generated that mayinclude interfamily strut swaps between struts of different families.Referring now to FIG. 22, an example process for generating a treatmentplan including an interfamily strut swap will now be described indetail. The treatment plan is for manipulating a fixator including ringsand struts to correct a deformity of first and second anatomicalstructure segments. The process of FIG. 22 is initiated at operation2210, at which positions and orientations of the first and secondanatomical structure segments in three-dimensional space are determinedby a computing system. Various example processes for determiningpositions and orientations of the first and second anatomical structuresegments in three-dimensional space are described in detail above (suchas with respect to operation 322 of FIG. 3A and based on operations310-322 of FIG. 3A), for example using the frame matching processesdescribed above. In some examples, images of the anatomical structuresegments and the fixator attached thereto may be acquired, indicationsof known geometries (e.g., geometries of fixator elements) and oflocations of fixator elements and anatomical structure segments in theimages may be received and used to determine the positions andorientations of the first and second anatomical structure segments inthree-dimensional space.

At operation 2212, manipulations to the fixator for correction of thedeformity are determined by the computing system. A number of exampletechniques for determining manipulations to a fixator for correcting ananatomical structure deformity are described in detail above (such aswith respect to operation 338 of FIG. 3B and based on operations 310-338of FIGS. 3A-3B) and are not repeated here. In some examples, themanipulations may be determined by determining desired changes to thepositions and/or orientations of the anatomical structure segments, forinstance how the anatomical structure segments can be repositioned withrespect to each other in order to promote union between the anatomicalstructure segments. The required changes to the geometry of the fixatorhat can enable the desired changes to the positions and/or orientationsof the anatomical structure segments can be computed, for example usingthe matrix algebra described above. In some examples, the manipulationsmay be determined based at least in part on various treatment planoptions (e.g. duration, distraction rate, etc.) such as described abovewith reference to operation 336 of FIG. 3B.

As set forth above, the manipulations include a plurality of adjustmentsto strut lengths. In the example of FIG. 22, however, the determinedmanipulations may also include an interfamily strut swap between a firststrut in a first strut family and a second strut in a second strutfamily. As set forth above, a strut swap is a swap (i.e., exchange) of areplaced strut for a different sized replacement strut by removing thereplaced strut from the fixator and replacing it with the replacementstrut. As set forth above, certain conventional software programs mayallow only intrafamily strut swaps between struts within the samefamily. By contrast, the manipulations determined at operation 2212include at least one interfamily strut swap from a first strut in afirst strut family to a second strut in a second strut family. The firststrut family may include a first plurality of struts having differentsize ranges with respect to one another and the second strut family mayinclude a second plurality of struts having different size ranges withrespect to one another. In some examples, the first strut family may bea standard strut family and the second strut family may be a quickadjust strut family. In other examples, the first strut family may be aquick adjust strut family and the second strut family may be a standardstrut family. In some examples, a first maximum length of a longeststrut in the first strut family may be longer than a second maximumlength of a longest strut in the second strut family. For example, insome cases, a maximum length of a longest quick adjust strut may belonger than a maximum length of a longest standard strut. Also, in someexamples, a first minimum length of a shortest strut in the first strutfamily may be shorter than a second minimum length of a shortest strutin the second strut family. For example, a minimum length of a shorteststandard strut may be shorter than a minimum length of a shortest quickadjust strut. Thus, by allowing at least one interfamily strut swap, thetreatment plan may allow struts to be lengthened and/or shortened tolengths that may not be achievable using on only intrafamily strut swapsbetween struts in a single family.

As should be appreciated, the ability to include interfamily strut swapsin a treatment plan may raise the complexity of calculating thetreatment plan because, in some cases, multiple different possiblecombinations of different strut swaps could be employed in order toeventually result in correction of the deformity, for example becausesize ranges of struts from different families may at least partiallyoverlap one another at various different lengths. In some examples, anumber of optimization rules may be employed in order to allow thesoftware to select and calculate a particular treatment plan (i.e., setof strut adjustments) from a number of potential available treatmentplans. For example, an inclusion of the interfamily strut swap in themanipulations may be based on a determination that the correction of thedeformity cannot be performed using struts from only a single strutfamily. In some cases, a user may select a preferred strut family. Ifthe correction can be accomplished using only struts from the preferredstrut family, then a treatment plan may be generated that includes onlyintrafamily strut swaps within the preferred strut family. Interfamilystrut swaps may be employed only when it is determined that thecorrection cannot be accomplished using only struts from the preferredstrut family.

In some examples, if the correction can be accomplished only by using atleast one strut from a non-preferred family, then a decision tree may becreated that represents all possible strut swap scenarios for a givenstrut based on the initially mounted strut type and the strut lengthvalues for each treatment step. Different paths through the decisiontree may then represent different strut swap plans. For each strut nodein the tree, a cost function may calculate the costs of a potentialstrut swap between a parent strut type and a current strut type. Thesecost functions may allow the optimization and selection of a strut swapplan. In some examples, the strut swap plan may be created according tothe path through the decision tree with the lowest costs. In someexamples, a potential goal of the optimization may include reducing thenumber of required strut swaps in the selected strut swap plan. In somecases, this goal may be accomplished by assigning a higher cost to theact of performing each additional strut swap in comparison to other costfactors (e.g., strut swap range duration, etc.). In some examples, themanipulations to the fixator may be determined based at least in part ona rule to select a treatment plan with a fewest amount of strut swapsfrom a plurality of available treatment plans. Another potential goal ofthe optimization may include optimizing the strut swap range duration inthe selected strut swap plan. Specifically, in some cases, longer strutswap range durations (e.g., durations of four or more days) may bepreferred because they may give patients greater flexibility inselecting when strut swaps are performed. In some cases, this goal maybe accomplished by assigning a higher cost to shorter strut swap rangedurations in comparison to other cost factors (e.g., quantity of strutswaps, etc.). In some examples, the manipulations to the fixator may bedetermined based at least in part on a rule to select a treatment planwith at least one strut swap having at least a minimum threshold strutswap duration (e.g., at least four days) from a plurality of availabletreatment plans.

At operation 2214, indications of the manipulations to the fixator areprovided, by the computing system, to one or more users. Various exampletechniques for providing indications of manipulations to a fixator aredescribed above, for example with respect to operations 340-342 of FIG.3B and FIGS. 11-13. For example, chart 1130 of FIG. 12 may includeday-by-day manipulation information for each strut within the fixationapparatus. Additionally, a calendar 1140 of FIG. 13 may indicate rangesof dates on which strut swaps may be performed. Furthermore, day-by-daygraphical representations of the fixator that indicate strut swapranges, for example as shown in FIGS. 15-21 and described above, mayalso be employed. It is noted that, in some examples, the strut swaprange indication techniques described above, such as with respect toFIG. 14, may be used to indicate swap ranges for either or both ofintrafamily and interfamily strut swaps. Any combination of these andother techniques may be used. Upon being provided with the indicationsof the manipulations to the fixator, one or more users may implement theindicated adjustments, including performing one or more interfamilystrut swaps, in order to correct the deformity of the anatomicalstructure segments.

Example Computing Device

Referring to FIG. 23, a suitable computing device such as examplecomputing device 78 can be configured to perform any or all of thetechniques set forth above. It will be understood that the computingdevice 78 can include any appropriate device, examples of which includea desktop computing device, a server computing device, or a portablecomputing device, such as a laptop, tablet, or smart phone.

In an example configuration, the computing device 78 includes aprocessing portion 80, a memory portion 82, an input/output portion 84,and a user interface (UI) portion 86. It is emphasized that the blockdiagram depiction of the computing device 78 is exemplary and notintended to imply a specific implementation and/or configuration. Theprocessing portion 80, memory portion 82, input/output portion 84, anduser interface portion 86 can be coupled together to allowcommunications therebetween. As should be appreciated, any of the abovecomponents may be distributed across one or more separate devices and/orlocations.

In various embodiments, the input/output portion 84 includes a receiverof the computing device 78, a transmitter of the computing device 78, ora combination thereof. The input/output portion 84 is capable ofreceiving and/or providing information pertaining to communicate anetwork such as, for example, the Internet. As should be appreciated,transmit and receive functionality may also be provided by one or moredevices external to the computing device 78.

The processing portion 80 may include one or more processors. Dependingupon the exact configuration and type of processor, the memory portion82 can be volatile (such as some types of RAM), non-volatile (such asROM, flash memory, etc.), or a combination thereof. The computing device78 can include additional storage (e.g., removable storage and/ornon-removable storage) including, but not limited to, tape, flashmemory, smart cards, CD-ROM, digital versatile disks (DVD) or otheroptical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, universal serial bus (USB)compatible memory, or any other medium which can be used to storeinformation and which can be accessed by the computing device 78.

The computing device 78 also can contain the user interface portion 86allowing a user to communicate with the computing device 78. The userinterface 86 can include inputs that provide the ability to control thecomputing device 78, via, for example, buttons, soft keys, a mouse,voice actuated controls, a touch screen, movement of the computingdevice 78, visual cues (e.g., moving a hand in front of a camera on thecomputing device 78), or the like. The user interface portion 86 canprovide outputs, including visual information (e.g., via a display),audio information (e.g., via speaker), mechanically (e.g., via avibrating mechanism), or a combination thereof. In variousconfigurations, the user interface portion 86 can include a display, oneor more graphical user interfaces, a touch screen, a keyboard, a mouse,an accelerometer, a motion detector, a speaker, a microphone, a camera,a tilt sensor, or any combination thereof. Thus, a computing systemincluding, for example, one or more computing devices 78 can include aprocessor, a display coupled to the processor, and a memory incommunication with the processor, one or more graphical user interfaces,and various other components. The memory can have stored thereininstructions that, upon execution by the processor, cause the computersystem to perform operations, such as the operations described above. Asused herein, the term computing system can refer to a system thatincludes one or more computing devices 78. For instance, the computingsystem can include one or more server computing devices that communicatewith one or more client computing devices.

While example embodiments of devices for executing the disclosedtechniques are described herein, the underlying concepts can be appliedto any computing device, processor, or system capable of communicatingand presenting information as described herein. The various techniquesdescribed herein can be implemented in connection with hardware orsoftware or, where appropriate, with a combination of both. Thus, themethods and apparatuses described herein can be implemented, or certainaspects or portions thereof, can take the form of program code (i.e.,instructions) embodied in tangible non-transitory storage media, such asfloppy diskettes, CD-ROMs, hard drives, or any other machine-readablestorage medium (computer-readable storage medium), wherein, when theprogram code is loaded into and executed by a machine, such as acomputer, the machine becomes an apparatus for performing the techniquesdescribed herein. In the case of program code execution on programmablecomputers, the computing device will generally include a processor, astorage medium readable by the processor (including volatile andnon-volatile memory and/or storage elements), at least one input device,and at least one output device, for instance a display. The display canbe configured to display visual information. The program(s) can beimplemented in assembly or machine language, if desired. The languagecan be a compiled or interpreted language, and combined with hardwareimplementations.

It should be appreciated that the orthopedic fixation with imageryanalysis techniques described herein provide not only for the use ofnon-orthogonal images, but also allow the use of overlapping images,images captured using different imaging techniques, images captured indifferent settings, and the like, thereby presenting a surgeon withgreater flexibility when compared with existing fixation and imagerytechniques.

The techniques described herein also can be practiced via communicationsembodied in the form of program code that is transmitted over sometransmission medium, such as over electrical wiring or cabling, throughfiber optics, or via any other form of transmission. When implemented ona general-purpose processor, the program code combines with theprocessor to provide a unique apparatus that operates to invoke thefunctionality described herein. Additionally, any storage techniquesused in connection with the techniques described herein can invariablybe a combination of hardware and software.

While the techniques described herein can be implemented and have beendescribed in connection with the various embodiments of the variousfigures, it is to be understood that other similar embodiments can beused or modifications and additions can be made to the describedembodiments without deviating therefrom. For example, it should beappreciated that the steps disclosed above can be performed in the orderset forth above, or in any other order as desired. Further, one skilledin the art will recognize that the techniques described in the presentapplication may apply to any environment, whether wired or wireless, andmay be applied to any number of such devices connected via acommunications network and interacting across the network. Therefore,the techniques described herein should not be limited to any singleembodiment, but rather should be construed in breadth and scope inaccordance with the appended claims.

What is claimed:
 1. A computer-implemented method for providing aplurality of fixator graphical representations of a fixator thatincludes rings and struts to correct a deformity of first and secondanatomical structure segments comprising: determining, by a computingsystem, manipulations to the fixator for correction of the deformity,the manipulations comprising a plurality of adjustments to strut lengthsand a strut swap from a replaced strut to a replacement strut, whereinthe manipulations are performed throughout a set of stages, wherein thestrut swap is performable in a strut swap range comprising a sub-set ofstages within the set of stages, the sub-set of stages including a swapstart stage and a swap end stage; and generating, by the computingsystem, the plurality of fixator graphical representations, wherein theplurality of fixator graphical representations include a swap startfixator graphical representation and a swap end fixator graphicalrepresentation, wherein each of the plurality of fixator graphicalrepresentations includes a respective one of a plurality of replacedstrut graphical representations and a respective one of a plurality ofreplacement strut graphical representations, wherein the plurality ofreplaced strut graphical representations change from a first renderingstate in the swap start fixator graphical representation to a secondrendering state in the swap end fixator graphical representation, andwherein the plurality of replacement strut graphical representationschange from the second rendering state in the swap start fixatorgraphical representation to the first rendering state in the swap endfixator graphical representation.
 2. The computer-implemented method ofclaim 1, wherein each stage in the set of stages is a respective day. 3.The computer-implemented method of claim 1, wherein the first renderingstate is a more opaque state and the second rendering state is a lessopaque state that is less opaque than the more opaque state.
 4. Thecomputer-implemented method of claim 1, wherein the plurality ofreplaced strut graphical representations and the plurality ofreplacement strut graphical representations have linear rates of changebetween the first rendering state and the second rendering state.
 5. Thecomputer-implemented method of claim 4, wherein the plurality of fixatorgraphical representations include one or more intermediate fixatorgraphical representations that represent the fixator at one or moreintermediate stages between the swap start stage and a swap end stage,and wherein the one or more intermediate fixator graphicalrepresentations are rendered according to the linear rates of change. 6.The computer-implemented method of claim 1, wherein the plurality offixator graphical representations are three-dimensional graphicalrepresentations of the fixator.
 7. The computer-implemented method ofclaim 1, wherein the plurality of replaced strut graphicalrepresentations may fade out from the swap start stage to the swap endstage, and wherein the plurality of replacement strut graphicalrepresentations may fade in from the swap start stage to the swap endstage.
 8. A computer-implemented method for generating a treatment planfor manipulating a fixator including rings and struts to correct adeformity of first and second anatomical structure segments comprising:determining, by a computing system, positions and orientations of thefirst and the second anatomical structure segments in three-dimensionalspace; determining, by the computing system, manipulations to thefixator for correction of the deformity, the manipulations comprising aplurality of adjustments to strut lengths and an interfamily strut swapbetween a first strut in a first strut family and a second strut in asecond strut family; and providing, by the computing system, to one ormore users, indications of the manipulations to the fixator.
 9. Thecomputer-implemented method of claim 8, wherein the first strut familyincludes a first plurality of struts having different size ranges withrespect to one another and the second strut family includes a secondplurality of struts having different size ranges with respect to oneanother.
 10. The computer-implemented method of claim 8, wherein aninclusion of the interfamily strut swap in the manipulations is based ona determination that the correction of the deformity cannot be performedusing struts from only a single strut family.
 11. Thecomputer-implemented method of claim 8, wherein the manipulations aredetermined based at least in part on a rule to select a treatment planwith a fewest amount of strut swaps from a plurality of availabletreatment plans.
 12. The computer-implemented method of claim 8, whereinthe manipulations are determined based at least in part on a rule toselect a treatment plan with at least one strut swap having at least aminimum strut swap duration from a plurality of available treatmentplans.
 13. The computer-implemented method of claim 8, wherein the firststrut family is a standard strut family and the second strut family is aquick adjust strut family.
 14. The computer-implemented method of claim8, wherein a first maximum length of a longest strut in the first strutfamily is longer than a second maximum length of a longest strut in thesecond strut family.
 15. The computer-implemented method of claim 8,wherein a first minimum length of a shortest strut in the first strutfamily is shorter than a second minimum length of a shortest strut inthe second strut family.
 16. One or more non-transitorycomputer-readable storage media having stored thereon instructions that,upon execution by one or more computing devices, cause the one or morecomputing devices to perform operations for providing a plurality offixator graphical representations of a fixator that includes rings andstruts to correct a deformity of first and second anatomical structuresegments comprising: determining, by a computing system, manipulationsto the fixator for correction of the deformity, the manipulationscomprising a plurality of adjustments to strut lengths and a strut swapfrom a replaced strut to a replacement strut, wherein the manipulationsare performed throughout a set of stages, wherein the strut swap isperformable in a strut swap range comprising a sub-set of stages withinthe set of stages, the sub-set of stages including a swap start stageand a swap end stage; and generating, by the computing system, theplurality of fixator graphical representations, wherein the plurality offixator graphical representations include a swap start fixator graphicalrepresentation and a swap end fixator graphical representation, whereineach of the plurality of fixator graphical representations includes arespective one of a plurality of replaced strut graphicalrepresentations and a respective one of a plurality of replacement strutgraphical representations, wherein the plurality of replaced strutgraphical representations change from a first rendering state in theswap start fixator graphical representation to a second rendering statein the swap end fixator graphical representation, and wherein theplurality of replacement strut graphical representations change from thesecond rendering state in the swap start fixator graphicalrepresentation to the first rendering state in the swap end fixatorgraphical representation.
 17. The one or more non-transitorycomputer-readable storage media of claim 16, wherein the first renderingstate is a more opaque state and the second rendering state is a lessopaque state that is less opaque than the more opaque state.
 18. The oneor more non-transitory computer-readable storage media of claim 16,wherein the plurality of replaced strut graphical representations andthe plurality of replacement strut graphical representations have linearrates of change between the first rendering state and the secondrendering state.
 19. The one or more non-transitory computer-readablestorage media of claim 18, wherein the plurality of fixator graphicalrepresentations include one or more intermediate fixator graphicalrepresentations that represent the fixator at one or more intermediatestages between the swap start stage and a swap end stage, and whereinthe one or more intermediate fixator graphical representations arerendered according to the linear rates of change.
 20. The one or morenon-transitory computer-readable storage media of claim 16, wherein theplurality of replaced strut graphical representations may fade out fromthe swap start stage to the swap end stage, and wherein the plurality ofreplacement strut graphical representations may fade in from the swapstart stage to the swap end stage.